Build a Room Ioniser Circuit Diagram

This is a voltage multiplier circuit acting as an Room Ioniser Circuit Diagram. Its calculated to feed 220V from mains and the output is about 6KV. Caution should take with the circuit as can be dangerous due to mains. You can place a needle at the output 3cm long. Even you disconnect from mains, capacitors can be dangerous so make sure to discharge them by shorting their pins before you touch the circuit with hands.

Room Ioniser Circuit Diagram

 

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A Simple MD Catridge Preamplifier

Phonographs are gradually becoming a rarity. Most of them have had to yield to more advanced systems, such as CD players and recorders or (portable) MiniDisc player/recorders. This trend is recognized by manufacturers of audio installations, which means that the traditional phono input is missing on increasingly more systems. Hi-fi enthusiasts who want make digital versions of their existing collections of phonograph records on a CD or MD, discover that it is no longer possible to connect a phonograph to the system.

Circuit diagram :

A Simple MD Catridge Preamplifier Circuit Diagram

However, with a limited amount of circuitry, it is possible to adapt the line input of a modern amplifier or recorder so that it can handle the low-level signals generated by the magnetodynamic cartridge of a phonograph. Of course, the circuit has to provide the well-known RIAA correction that must be used with these cartridges. The preamplifier shown here performs the job using only one opamp, four resistors and four capacitors. For a stereo version, you will naturally need two of everything. Any stabilized power supply that can deliver ±15V can be used as a power source.

Author : H. Steeman

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Roma has developed a small E17 LED Light Bulb

Roma has developed a small LED bulb "LDA4L-G-E17" can support E17 lamp holder, compare with the original LED bulbs such as 12 volt LED lights, new products reduce the size of the power part, the shade of the hemispherical shape is more nearly spherical. LED light source module use the COB construct without mirror, the shape almost identical to  old-fashioned small krypton bulb to achieve 180°light distribution angle.

Prior to the disadvantage of small LED bulb is less luminous part of the light distribution angle narrow, dark horizontal and supply side. The brightness of the new product is equivalent to a 25W mini krypton bulb. The shade is made of the proliferation of Roma self-developed material that can be issued does not point to the warmth of light. The bulb the total luminous flux of 265lm, the power consumption of 4W. The light color than incandescent light color. Design life (the luminous flux dropped to 70% of the initial time) is approximately 40,000 hours. Pricing is open, expect the actual price of less than 2000 yen.

By the way, I konw where to buy the LED lighting such as LED light and best led flashlight at low price,

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Make a Simple Refrigerator Thermostat

Want to make an accurate electronic refrigerator thermostat for your refrigerator? The circuit of a solid state thermostat described in this article will surprise you with its “cool” performance. The unit once built and integrated with any relevant appliance will instantly start exhibiting an improved control of the system saving electricity and also increasing the life of the appliance.

Conventional refrigerator thermostats are expensive and not very accurate. Moreover these are prone to wear and tear and therefore not permanent. A simple and much efficient electronic refrigerator thermostat device is discussed here.

A thermostat as we all know is a device which is able to sense a particular set temperature level and trip or switch an external load. Such devices can be electromechanical types or more sophisticated electronic types. Thermostats typically are associated with air conditioning, refrigeration and water heating appliances. For such applications the device becomes a critical part of the system without which the appliance may reach and start operating under extreme conditions and ultimately get damaged. Adjusting the control switch provided in the above appliances ensures that the thermostat cuts off power to the appliance once the temperature crosses the desired limit and switches back as soon as the temperature returns to the lower threshold. Thus the temperature inside refrigerators or a room temperature through an Air conditioner is maintained to favorable ranges.

The circuit idea of a refrigerator thermostat presented here can be used externally over a refrigerator or any similar appliance to control its operation. Controlling their operation cab be done by attaching the sensing element of the thermostat to the external heat dissipating grid normally situated behind most cooling devices that use Freon. The design is more flexible and wide ranged compared to the built-in thermostats and is able to exhibit better efficiency. The circuit can easily replace the conventional low tech designs and moreover it’s much cheaper compared to them.

Let’s understand how the circuit functions:

Parts List

R1=10k NTC,

R2=Preset 10K

R3,R4=10K

R5=100K

R6=510E

R7=1K

R8=1M

R9=56 OHM/1watt

C1=105/400V

C2=100uF/25V

D1=1N4007

Circuit Description

  The diagram alongside shows a simple circuit built around the IC 741, which is basically configured as a voltage comparator.

A transformer less power supply is incorporated here to make the circuit compact and solid-state.

A bridge configuration comprising R3, R2, P1 and the NTC R1 at the input forms the main sensing elements of the circuit.

The inverting input of the IC is clamped at half the supply voltage using a voltage divider network of R3 and R4.

This eliminates the need of providing a dual supply to the IC and the circuit is able to produce optimum results even through single pole voltage supply.

The reference voltage to the non-inverting input of the IC is fixed through the preset P1 with respect to the NTC (Negative Temperature Coefficient.)

In case the temperature under check tends to drift above the desired levels, the NTC resistance drops and the potential at non-inverting input of the IC crosses the set reference. This instantly toggles the output of the IC, which in turn switches the output stage comprising transistor, triac network, switching off the load (heating or the cooling system) until the temperature reaches the lower threshold.

The feedback resistor R5 to some extent helps to induce hysteresis into the circuit, an important parameter without which the circuit may keep flip-flopping quite rapidly in response to the sudden temperature changes.

Once the assembly is completed, setting up the circuit is very simple and is done with the following points:

REMEMBER THE ENTIRE CIRCUIT IS AT AC MAINS POTENTIAL, SO EXTREME CAUTION IS ADVISED WHILE GOING THE TESTING AND THE SETTING PROCEDURES. USE OF A WOODEN PLANCK OR ANY OTHER INSULATING MATERIAL UNDER YOUR FEET IS STRICTLY RECOMEMDED; ALSO USE ELECTRICAL TOOLS WHICH ARE THOROUGHLY INSULATED NEAR AND AROUND THE GRIPPING AREA.

You will need a sample heat source accurately adjusted to the desired cut-off threshold level of the thermostat circuit.

Switch on the circuit and introduce and attach the above heat source with the NTC.

Now adjust the preset so that the output just toggles (the output LED comes on.)

Remove the heat source away from the NTC, depending upon the hysteresis of the circuit the output should switch off within few seconds.

Repeat the procedure many times to confirm its correct functioning.

This concludes the setting up of this refrigerator thermostat and is ready to be integrated with any refrigerator or similar gadget for an accurate and permanent regulation of its operation.

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How to Make a Simple Piezo Buzzer Circuit Piezo Electric Buzzer Explained

In this article we will learn how to make a very simple piezo electric buzzer using hardly any electronic components. Just a single transistor, a coil, a piezo buzzer are enough to make it “buzz” or rather “twit” for you, with an output that may be quite ear piercing.

Circuit Description:

The buzzer circuit described here actually works in a quite unique way. Instead of the normal working concept employed by other forms of oscillators which require resistor and capacitor networks for generating the oscillations, this circuit use inductive feedback for the required operations.

Referring to the figure we find that the transistor T1 along with the inductor forms the heart of the circuit. Basically the coil which is specifically called the buzzer coil, is in fact positioned for amplifying the created oscillations while the actual feed back is provided by the center tap of the three terminal piezo element used for the present application.

When a voltage is introduced in the circuit, the transistor conducts, operating the piezo element across the buzzer coil, however this also leads to the grounding of the base of the transistor through the center tap of the piezo element, this instantly switches off the transistor and in turn the piezo also switches off, releasing the base of the transistor.

 The transistor reverts to its original state and the cycle repeats, generating oscillations or the required “buzzing” frequency.

The center tap from the piezo transducer plays an important role in sustaining the oscillations and therefore in this particular design we need a three terminal piezo rather than a two terminal one.

The oscillations produced at the collector of the transistor is dumped into the coil, saturating the coil with magnetic inductions. The coil kicks back the stored energy during the oscillations, magnifying the generated AC across it.

This stepped up AC is applied across the anode and the cathode of the piezo element, which starts vibrating sharply according the pitch of the frequency, generating a shrill, ear piercing sound in the air.

However to make the sound audible at maximum intensity, the piezo transducer needs to be stuck or installed in a special way inside its housing.

For this particular application the piezo element needs to be stuck at the base of its housing which must consist of a hole having a diameter of about 7 mm. 

The piezo element cannot be stuck directly over the base of the housing, rather it must stuck and positioned over a soft, pure rubber ring, having diameter 30 % less than that of the piezo transducer.

Only if the above fixing procedure is followed, the buzzer will sound, otherwise the sound may get choked and fail to reproduce.

 Parts List

R1 = 100K,
R2 = 4k7,
T1 = BC547,
L1 = Buzzer inductor,
PZ1 = Piezo element, 27mm, three terminal
Rubber ring = 22mm

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Triac Light Switch as a dimers

The series of light switches this time slightly different from the voltage of work. The series of light switches can work directly on the AC power network. Light switches are using the main component of TRIAC and LDR. The circuit is very simple and the components were sold in the market.

If you want a light reception sensitivity of this circuit can be arranged then the 3.3 MOhm resistor can be replaced with a variable resistor. For more details can be seen from the following series of images.

Circuit Diagram

With Triac Light Switch series is as dimers, but dimers control performed by the reception of light around the LDR. The lower the intensity cayaha received LDR then  bright lights. For installation LDR need to be considered so as not exposed to light from the lamp directly.

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How to Make a Dual Tone Siren Circuit

This electronic siren gives out a continuously varying high amplitude sound. Since the supply voltage is not critical, it can be used in cars, motor cycles or at home. It can replace the ordinary call bell. - . The circuit consists of two separate free running multivibrator and an oscillator.

A free running or astable multivibrator is one which has two quasi-stable states and the output of one stag is connected to the input of the other through a coupling capacitor.

Since both the states are quasi-stable, the output attained is continuously varying in nature i.e. high, low high low-.

 The output is in the form low pulses, the frequency of which depends on the base biasing resistor and the coupling capacitor, When these resistances and condensers for both the stages are of different values, the output ` wave form is rectangular; this is because the time constant of the two quasi-stable states becomes different.

If this time constant of the two, states is made the same, the output obtained then is square wave. Two states of the multivibrator are made identical by the use of the same values of components.

The components used in the circuit (Fig). result in a square wave output and the time constant selected is so as to give a fairly good rise and fall of the siren.

However, one may change the value of coupling capacitors to get any other desired time constant. The second unit is an oscillator section. The condenser connected at the output is the feed back condenser. It determines the tone of the siren.

Higher the value of the condenser the lower is the pitch. for high pitch sound (generally used in siren) feed-back condenser ranging from 0.047 uf to 0.1 mfd should be selected. The speaker may be metallic case (horn type) or small planer cone. The metallic cone horn gives better results.

Parts for dual tone siren circuit

R1,R2,R5,R6= 22K
R3,R4 = 2K2
R7 = 10 Ohms, 1 watt
C1,C2,C4 = 0.1uF
C3 = 22uF/25V
T1,T2 = BC557
T3 = BC547
T4 = 2N2907 or 8550

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A Simple Function Generator

This is a simple function generator circuit that can produce the following waveforms: square wave, triangular wave, and sine wave.

   

The circuits main components are two 1458 ICs.  The 1458 is a dual op-amp IC, i.e., an IC that houses two op amps inside it.  The circuit uses four op amps, two from each 1458.

  

The bottom-most op amp in Figure 1 is configured as an astable multivibrator, which continuously generates a square wave.  Assume that C1 has no charge initially. The voltage at the inverting input is zero, while the voltage at the non-inverting input is very slightly positive (a ratio of the op amps output offset voltage as determined by R1 and R2). This minute voltage difference at the inputs is enough to cause the op amps output to swing to high.

  

When the output becomes high, C1 starts charging up. The voltage at the inverting input soon exceeds that at the non-inverting input, forcing the output to swing to low, which discharges C1 again.  At a certain point, the voltage at the non-inverting input exceeds that at the inverting input again, and the output of the op amp goes high again.

   

This cycle wherein the first op amps output swings between low and high goes on indefinitely, generating the square wave.

  

The two middle op-amps are both configured as integrators. The input to the second op amp is the square wave output of the first op amp.  Being configured as an integrator, this op amp outputs a triangular wave (the integral of a square wave), as shown in Figure 1. 

    

The triangular wave output of the second op amp is then fed into the third op amp, which is also configured as an integrator.  The output of the third op amp is a sine wave (the integral of a triangular wave).

   

The sine wave output of the third op amp is fed into the fourth op amp, which is configured as an inverting amplifier. The output of this last op amp is also a sine wave but opposite in phase as its input. link

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How to Installation A Car Stereo

Car Stereo Installation Guide - Want to save some money? Ever wonder if you could do a car stereo installation yourself? Yes, you can do it yourself! Go ahead, spend that money on your hardware! Don’t spend it on labor. Besides, doing a car stereo installation yourself can be a very rewarding experience, not to mention you can learn a lot from it too. Nothing beats the feeling of seeing your “creation” in action, running smoothly and perfectly.

But be very careful, you really won’t want to damage your expensive hardware. Well, most car audio hardware are no-brainers to install, you’d find that most of the time the parts have specially shaped sockets and slots etc. and would only fit where it’s supposed to be installed. Still, it’s best to proceed methodically.

In a car stereo installation, you have to determine what kind of rig you’re going to put into your vehicle. If you’re a beginner, it’s best you do a car stereo installation if it’s just a simple system. You may want to leave the complicated stuff to the professionals, like installing delicate equipment like LCD panels, motorized parts etc. especially if it requires the creation of custom panels and such. 

Head units are one of the easiest to do in a car stereo installation. Fortunately, most units follow the same size standards (DIN). In many cars, once the factory radio is removed the aftermarket radio will fit in the hole. In many other cars, a kit is needed if the factory hole is too big, or not deep enough. In some cases the dash has to be cut.  Any car stereo store should have kits required for installation. 

There are two types of mounting in a car stereo installation. ISO mounting is when the radio can be screwed to existing factory radio brackets, such as in most Japanese cars. Ring mounting is when an aftermarket radio comes with a metal ring that gets mounted to the factory radio hole or aftermarket kit via bendable tabs. In many cars, dash and trim rings have to be filed to enlarge the radio hole. Once the ring is installed, the radio slides in and is held by snaps. In most cases, special tools are required to remove the radio.

Speakers are very critical in a car stereo installation. No matter how expensive your speakers are, if they are not properly installed, the sound will not be up to par.

In a simple car stereo installation, you’ll probably be using speakers that fit into a factory location. Just make sure there are no gaps or holes. Sometimes building a wood or fiberglass baffle helps reduce holes and gives you much better sound. But always be careful when using power tools around speakers. Car stereo installation warranties usually dont cover holes in speakers.

For unconventional speaker locations, sometimes metal has to be cut. You might want to leave this to the professionals, tools like plasma cutters and pneumatics drills are required. But if you’re going to insist, a pair of metal snips (left and right cut) will do.

A car stereo installation has to put up with vibrations and other noise sources in its environment. Even though it is impossible to eliminate these completely, there are products that will greatly decrease the noise and rattling, particularly on non-luxury cars. Liners, sprays and adhesive strips and even carpeting applied onto the panels can make a world of difference.   

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a simple DC voltage booster

Joule Thief: a simple DC voltage booster

A joule thief circuit lit from a 0.5V AAA battery. Click to enlarge.

A Joule thief is a simple circuit that acts as a DC to DC booster, raising a supply voltage by several volts. In this iteration it uses the exhausted voltage of a alkaline battery and boosts it enough to light a blue LED that requires 2.8V to light. With an otherwise dead 0.5V AAA battery, it will light a blue LED and run for days, using (at the moment) just under 2mA of current. Its much much dimmer than using a fresh battery or running the LED with a proper current through it. Giving the Joule thief circuit 3V from two fresh batteries pulls 75mA through the LED, making it very, very bright and probably short-lived.

A schematic is below. The circuit works like this: When first turned on, current flows into the inductor and produces a magnetic field in the toroid. While this is happening, no voltage appears at the base of the transistor, so the transistor remains off. The LED sees at first no voltage and while the inductor fills up, it only sees a maximum voltage of the battery, which is not enough to pass the diode. Once the inductor is charged, the battery voltage appears at the base of the transistor, turning it on. This allows the right side of the inductor to want to dump the energy it has stored in its magnetic field as quickly as possible, and this gives us a high-voltage that appears across the inductor. When that voltage exceeds 2.8V the LED turns on and lights up until the voltage drops below, triggering the sequence to begin again. I measured the frequency of the on/off oscillation and it seems to run at about 34kHz; the multimeter said between 68 and 72kHz but a radio showed there was 34kHz signal as well, which I assume was the fundamental (and the 68kHz one a harmonic). It did change in frequency a bit while on.

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How to Build a Pyro ignition Circuit Electronic Pyro Igniter system

The
following conversation was made by Mr.Tom and me regarding the circuit
idea of a pyro-iginition system. I was asked to design
the particular circuit idea by Mr.Tom in Fiverr.com.
The discussion explains the details of his requirement and how it was almost fulfilled by me
I was wondering if you could design me a system for a simple pyrotechnic firing system. 
An input trigger would (maybe 5-12v) pulse would switch on que1, another pulse would switch cue2 (binary counter). 

A
total of 16 channels (cues), each cue would be fired with from mosfet
pair. Ideally control circuit would have independent power supply to
power to cues. 

It
would also be nice to have a timer which could on pulse fire each cue
in sequence e.g. cue1 wait 1 second cue 2 wait 1 second cue3 etc. 

Either this of some kind of programmable pic (picaxe etc) so the functionality can be changed. 

Kind regards 
Tom

Hi Tom,
I
can design the control circuit along with the timer, however Im
interested to know what would be connected to the mosfet outputs,
because that looks the difficult part if Im required to set up those.

Thanks
Swagatam

Heres the pyro-ignition control circuit:

Next up is the mosfet output stage:

Hi Swagatam,
I dont seem to be able to get the control circuit to work.
Where does the external trigger connect to, if i connect a ground just before R5 can I use this as the trigger?
Thanks
Tom

Hi Tom,

The circuit starts sequencing the moment power is switched ON, so the "power ON" switch itself acts as the external trigger.

When
power is switched OFF, the circuit resets and comes to its original
state, so that when power is switched ON again, the cycle can repeats.

Thanks,
Swagatam

Hi Swagatam,
Thats not what I asked for.
The external trigger should either start the timing sequence if selected or step through each output on each trigger input.
Referringback to the conversation
"
Function 1
Trigger -> Cue 1 fires (stays on for 100ms to ignite firework)
Trigger -> Cue 2 fires (stays on for 100ms)

Function 2
Trigger -> Fires all Cues in sequence (cue 1,2,3 etc) from a internal modifiable timer

Function 3
The
circuit diagram also has continuity test for each cue, this should be a
low enough current as not to fire igniter this is to be displayed
through an led on each cue.
"

Regards
Tom

Hi Swagatam,
Ive attached a circuit diagram of an open source wireless firing system, the files can be found here
http://code.google.com/p/openpyro/downloads/list.
The system will fire these http://www.category4.co.uk/igniters/technical/igniters.php
If
youre just using a binary counter I think you might need to double the
stages(bits) and pulse the clock after 100ms to turn off the mosfets in
case of short circuit.

If you could replicate attached circuit without the wireless this would be fantastic. Ill pay for extra gigs if needed.
Thanks
Tom

Hi Tom,
From the above description what I understood is that the particular fireworks needs to be ignited in some sequence.

The
fuses would be loaded across the relevant mosfets and the triggering
timing would be such that the mosfets are switched only for some
fraction of a second, just enough to ignite the fireworks and then shut
off.
The sequence will go on repeating until the last mosfet is fired...am I correct?
If
my interpretation is right then I can go ahead with the circuit and
design it using ordinary discrete components, no need of any
microcontrollers.

Thanks,
Swagatam

Yes,
Function 1
Trigger -> Cue 1 fires (stays on for 100ms to ignite firework)
Trigger -> Cue 2 fires (stays on for 100ms)

Function 2
Trigger -> Fires all Cues in sequence (cue 1,2,3 etc) from a internal modifiable timer

Function 3
The
circuit diagram also has continuity test for each cue, this should be a
low enough current as not to fire igniter this is to be displayed
through an led on each cue.

Could this led be also lit when the cue is fired.
Tom

OK, function1 refers to a manual triggering option in the circuit? right?

There should be power to the circuit at all times, when a plus trigger is applied to the system it should step.

Hi Tom,
In our circuit this can be done through a simpler modification, kindly view the attachment.
Pressing S1 initiates the sequencing at any instant and releasing it stops the process.

Thanks
Swagatam.

OK let me try an explain again.
The circuit is a stepper, each trigger pulse it receives progresses the binary counter on one.
So trigger +12 v, binary counter increases one.
Trigger again +12v, binary counter increases one again.
The trigger pulse it totally separate from this circuit and comes from another source.
Easy enough, just a binary counter and outputs.

I
also want another function to allow the first trigger pulse to start a
timer a clock the binary counter on its own. This time is variable. So
there would be a switch to allow you to access this mode. So binary
counter output 1 would feed back into the timer circuit if a switch was
closed.

Hi Tom,
Just have a look at this modification, I hope this one works as intended.
S2 is a SPDT switch, when positioned toward B, it responds to the pressing of S1 and steps with each trigger from S1.
When S2 is moved toward A, pressing S1 does the following things:
T1 and T2 instantly latches powering the timer IC 4060 via T2 and T3.
IC 4060 starts clocking the IC 4017 for the required actions.
Putting
S2 back to point B resets the circuit to its previous mode, that is to
the manual mode. However to reset the IC 4017, it will need to be
switched OFF and then switched ON again.

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