TRIAC Light Dimmer

This little circuit can be used to dim lights up to about 350 watts. It uses a simple, standard TRIAC circuit that, in my expirience, generates very little heat. Please note that this circuit cannot be used with fluorescent lights.

Schematic

Parts

Part Total Qty. Description Substitutions R1 1 50K Pot R2 1 15K 1/2W Resistor C1, C2 2 0.068 250V Capacitor L1 1 Lamp To Be Controlled (up to 350 watts) L2 1 Neon Lamp TR1 1 40502 TRIAC MISC 1 Case, Knob, Heatsink For TR1, Wire, Socket For L1

Notes

1. This circuit is for 117VAC only. 220 or 240 V will burn up the circuit. L1 can be a maximum of 350 watts.
2. The circuit must be installed and used in a case.

Strobe Light

Disco anyone? Actually, this strobe serves a much more useful purpose then making it look cool when you dance in the dark. You can use it to view fast moving objects, look for craks in PC boards (hold the strobe on the trace side of the board and look from the component side), and it is a great attention getter in a store window.

    

Schematic

Parts

Part Total Qty. Description Substitutions R1 1 10 Meg, 1/4 Watt Resistor D1, D2 2 1N4003 Silicon Diode 1N4007 C1, C2 2 10uF 350V Capacitor C3 1 0.1uF 400 Volt Mylar Capacitor T1 1 4KV Trigger Transformer (see "Notes") FT 1 Flash Tube (see "Notes") L1 1 Neon Bulb Q1 1 106 SCR S1 1 115V 1A SPST Switch MISC 1 Case, Wire, Line Cord

Notes

Where To Get Parts).
1. This ciruits is NOT isolated from ground. Use caution when operating without a case. A case is required for normal operation. Do not touch any part of the circuit with the case open or not installed.
2. Most any diodes rated at greater then 250 volts at 1 amp can be used instead of the 1N4003's.

Simple Colour Organ

Schematic

Parts

Part Total Qty. Description Substitutions R1 1 500 Ohm Pot T1 1 500 Ohm/500 Ohm Matching Transformer 1K/1K Matching Transformer SCR1 1 C106Y SCR 106B, Teccor S2003LS1 L1 1 10-100 Watt Lamp MISC 1 Case, Board, Socket For L1, Line Cord

Notes

1. L1 can be any 10-100 Watt lamp.
2. R1 adjusts sensitivity. The greater the resistance, the less sensitive the colour organ becomes.
3. Since this project is powered by 120 VAC, it must be installed in a case.
4. You can also use the Teccor S2003LS1 SCR for SCR1. These give better sensitivity and brightness than the C106Y units.

Light/Dark Detector

Schematic

Parts

Part Total Qty. Description Substitutions R1 1 100K Pot Q1 1 2N3904 NPN Transistor 2N2222 Q2 1 NPN Phototransistor RELAY 1 9V Relay MISC 1 Board, Wire, 9V Battery Snap (if battery used), Knob For R1

Notes

1. R1 Adjusts sensitivity

LED Thermometer

Schematic

Parts

Part Total Qty. Description Substitutions C1 1 1uF 25V Electrolytic Capacitor C2 1 10uF 25V Electrolytic Capacitor R1 1 2.2K 1/4W Resistor R2, R5, R7 3 1K Trim Pot R3 1 1K 1/4W Resistor R4 1 1.5K 1/4W Resistor R6 1 470 Ohm 1/4W Resistor R8 1 100 Ohm Or 15 Ohm 1/4W Resistor (See Notes) D1 - D10 10 LED U1 1 LM34DZ Precision Fahrenheit Temperature Sensor U2 1 LM3914 Bar/Dot Graph Driver IC MISC 1 Board, Wire, Socket For U1 and U2, Case

Notes

1. The pinout of U1 depends on the version of the IC you purchase. These options are shown below:
   
2. You will want to build the circuit with U1 and U2 in sockets in order to be able to complete calibration (which requires removal of these ICs).
3. You can use any LED you want for D1 - D10, however blue LEDs have a higher voltage requirement so if you want to go blue for a modern look, they may appear more dim then red, yellow or green.
4. By leaving pin 9 of U2 disconnected, the graph will operate in dot mode and R8 should be 100 Ohm. If you build the circuit with pin 9 tied to 9V, the circuit will be in graph mode and R8 should be 15 Ohms.
5. To calibrate the circuit, you will need a voltmeter. Power the circuit up and let it sit for a few minutes for temperature to stabilize. Ground the negative lead of the meter and connect the positive lead to pins 6 and 7 of U2. Set R7 so the meter reads as close to 3.345V as possible. Now connect the positive lead of the meter to pin 4 of U2 and adjust R5 until the meter reads 2.545V. Finally, disconnect power to the circuit and remove U1 and U2 from their sockets. Measure the value of R3 with an ohmmeter and remember that value. Connect the ohmmeter across R1 and adjust R1 to a value of exactly 3 times the value of R3. Reinstall U1 and U2 and the circuit is ready for use.

LED Metronome Circuit

Schematic

Parts

Part Total Qty. Description Substitutions R1, R4, R6 3 10K 1/4W Resistor R2 1 1.5 Meg Linear Taper Pot R3 1 120K 1/4W Resistor R5 1 220 Ohm 1/4W Resistor C1, C3 1 0.1uF Ceramic Disc Capacitor C2, C4, C5 3 0.01uF Ceramic Disc Capacitor D1, D2, D13, D14 4 1N914 Signal Diode D3-D12 10 Jumbo Red LED Q1, Q2 2 2N3904 NPN Transistor U1 1 555 Timer IC U2 1 4029 CMOS Up/Down Counter IC U3, U4 2 4051 CMOS 8 Of 1 Switch IC U5 1 4011 CMOS Quad 2 Input NAND Gate IC SPKR 1 Small 8 Ohm Speaker S1 1 SPST Switch MISC 1 Board, Wire, Case, Sockets for ICs, Battery holder, Knob for R2

Notes

1. The circuit will reliably run from 6 to 12V. A typical 9V battery will be drained in several days by the LEDs with constant use. A 6V pack made from AA, C or D cells will last much longer.
2. The circuit will need some calibration before use. Calibration is fairly easy and accomplished by using a stopwatch to count the number of beats. You'll want to calibrate for 60 BPM (one per second), 120 BPM (two per second) and 180 BPM (3 per second). Just use your stopwatch to find the points of R2 that correspond to those beat rates and the mark the dial appropriately. Next find 90, 150 and 210 BPM. By that time you should then be able to evenly mark the remaining positions on the scale.
3. Blue LEDs need about 5V to light, so if you intend to use blue you will need to remove R5.
4. For an ideal metronome effect, the LEDs should be arranged in an arc.

LED Chaser

Schematic

Parts

Part Total Qty. Description Substitutions R1 1 1 Meg 1/4W Resistor R2 1 100K Pot R3 1 1K 1/4W Resistor 220Ohm if using blue LEDs C1 1 0.1uF 16V Ceramic Disk Capacitor U1 1 4011 CMOS NAND Gate U2 1 4017 CMOS Counter LED1-10 10 LEDs Of Any Colour MISC 1 Board, Sockets For ICs, Knob For R2

Notes

1. Use R2 to adjust the "chase rate".
2. You may need to use a lower value resistor if you wish to use blue LEDs. Try 220 Ohm.
3. You can also use incandescent lamps instead of LEDs. Use transistors to drive them by connecting the base of the transistors to each of the outputs of the 4017 through a 1K resistor. Connect one end of the lamp to the positive supply. Then connect the other end to the collector of the transistor. The emitter then goes to ground. Depending on the lamps, you may need power transistors that are heat sinked.
4. C1 may be replaced with a larger value for a slower "chase rate".
5. If you have problems with weird circuit behavior, try replacing R1 with a 33K resistor, and increasing C1 to 1uF.
6. If you plan to use this circuit in your car, be warned that in some areas it is illegal to have red, blue or yellow flashing lights unless you are an emergency vehicle.

LASER Transmitter/Receiver

Schematic Of Transmitter

Schematic Of Receiver

Parts

Part Total Qty. Description Substitutions C1, C2 2 0.1uf Ceramic Disc Capacitor C3 1 100uf 25V Electrolytic Capacitor R1 1 100K Ohm 1/4W Resistor R2 1 1M Ohm 1/4W Resistor R3 1 10K Pot Q1 1 NPN Phototransistor U1 1 741 Op Amp U2 1 LM386 Audio Amp SPKR1 1 8 Ohm Speaker T1 1 8 Ohm:2K Audio Transformer MISC 1 Wire, Board, Knob For R3, LASER Tube and Power Supply Notes In the transmitter schematic, no ballast resistor is shown because most small LASER power supplies already have one built in. Yours may differ, and a resistor may be needed. The receiver should be kept away from bright lights. You may want to put a piece of wax paper in front of Q1 to keep the LASER from swamping it. In order to get any decent amount of modulation, you may need to drive T1 with more then a watt. The circuit can be made to transmit computer data with the use of two modem chips.

IR Remote Switch Circuit

Schematic

Printed Circuit Board Layout

Printed Circuit Board Parts Placement

Parts

Part Total Qty. Description Substitutions R1 1 3 Meg 1/4W Resistor R2 1 1.2 Meg 1/4W Resistor R3 1 680 Ohm 1/4W Resistor R4 1 2K 1/4W Resistor R5 1 4.7K 1/4W Resistor R6 1 150 Ohm 1/4W Resistor C1 1 0.001uF Ceramic Disc Capacitor C2, C5 2 1uF 50V Tantalum Electrolytic Capacitor C3 1 47uF 50V Tantalum Electrolytic Capacitor C4 1 10uF 50V Tantalum Electrolytic Capacitor C5 1 150 Ohm 1/4W Resistor D1 1 1N4733 5V Zener Diode D2 1 1N4003 Rectifier Diode Q1 1 2N6071A TRIAC U1 1 GP1U52X IR Module U2 1 MC74HC74 D-Type Flip Flop U3 1 MOC3011 Opto Isolator MISC 1 Board, Sockets For ICs, Mains Socket, Mains Plug and Cord, Wire Notes Under normal circumstances, Q1 should not need a heatsink. The circuit is designed for a supply voltage of 120V. The printed circuit pattern is reproduced here larger then real life for clarity. It will need to be resized to the scale at the bottom of the image if you intend to transfer it to a board. The circuit functions as an on/off flip flop. Illuminate it with your remote once to turn it on, then again to turn it off.

IR Remote Control Jammer

Schematic

Parts

Part Total Qty. Description Substitutions R1 1 100K 1/4W Resistor R2 1 150K 1/4W Resistor R3 1 10K 1/4W Resistor R4 1 1K 1/4W Resistor R5 1 22 Ohm 1/4W Resistor See "Notes" C1 1 10nF Ceramic Disc Capacitor C2 1 1uF Electrolytic Capacitor D1, D2, D3 3 High Output IR LED Q1 1 2N4403 PNP Transistor Q2 1 2N4401 NPN Transistor S1 1 Normally Open Momentary Push Botton B1 1 4.5V Battery (Three "AA"'s In Series) MISC 1 Wire, Case, Board Notes Email Carl with questions, comments, etc. You may need to adjust the value of R3 for the right frequency. A pot can be used. You may only need one IR LED. It goes without saying that this circuit should be used with descretion. The value of R5 depends on your supply voltage and LED. For a standard 4.5V supply and standard IR LED, use 22 Ohm as specified on the parts list. This forum topic covers this resistor as well as a few other issues with the circuit.

IR Remote Extender Circuit

Schematic

Parts

Part Total Qty. Description Substitutions R1, R6 2 10K 1/4W Resistor R2 1 1K 1/4W Resistor R3 1 10K Linear Pot R4 1 2.2K 1/4W Resistor R5 1 47 Ohm 1/4W Resistor C1 1 0.01uF Ceramic Disc Capacitor Q1, Q2 2 2N3904 NPN Transistor D1 1 IR LED Radio Shack 276 143C U1 1 GP1U52X IR Module U2 1 TLC555 CMOS Timer LMC555, 7555 MISC 1 Board, Sockets For U2, Wire Notes Only the CMOS TLC555 timer can be used in this circuit. The original NE555 cannot operate reliably at 40KHz. Acceptable substitutions are shown in the parts list. Almost all powerful IR LEDs can be used for D1 if the appropriate value of R5 is chosen. To calibrate the circuit, use a frequency counter. Connect it in parallel with D1 and then ground the base of Q1. Adjust R3 for 40KHz on the counter. If a counter is not available, you will just have to point a remote at the circuit, press a button, and then adjust R3 until it works. This can take a few tries as not all remotes transmit continuously. If you intend to remotely mount D1 any great distance, you will need to use shielded cable. Connect the shield to circuit ground.

Infa-Red Remote Control

Schematic For Transmitter

Schematic For Receiver

Parts

Part Total Qty. Description Substitutions R1 1 22K 1/4W Resistor R2 1 1 Meg 1/4W Resistor R3 1 1K 1/4W Resistor R4, R5 2 100K 1/4W Resistor R6 1 50K Pot C1, C2 2 0.01uF 16V Ceramic Disk Capacitor C3 1 100pF 16V Ceramic Disk Capacitor C4 1 0.047uF 16V Ceramic Disk Capacitor C5 1 0.1uF 16V Ceramic Disk Capacitor C6 1 3.3uF 16V Electrolytic Capacitor C7 1 1.5uF 16V Electrolytic Capacitor Q1 1 2N2222 NPN Silicon Transistor 2N3904 Q2 1 2N2907 PNP Silicon Transistor Q3 1 NPN Phototransistor D1 1 1N914 Silicon Diode IC1 1 LM308 Op Amp IC IC2 1 LM567 Tone Decoder LED1 1 Infa-Red LED RELAY 1 6 Volt Relay S1 1 SPST Push Button Switch B1 1 3 Volt Battery Two 1.5V batteries in series MISC 1 Board, Sockets For ICs, Knob For R6, Battery Holder RELAY 1 6 Volt Relay Schematic For Transmitter Schematic For Receiver Parts Part Total Qty. Description Substitutions R1 1 22K 1/4W Resistor R2 1 1 Meg 1/4W Resistor R3 1 1K 1/4W Resistor R4, R5 2 100K 1/4W Resistor R6 1 50K Pot C1, C2 2 0.01uF 16V Ceramic Disk Capacitor C3 1 100pF 16V Ceramic Disk Capacitor C4 1 0.047uF 16V Ceramic Disk Capacitor C5 1 0.1uF 16V Ceramic Disk Capacitor C6 1 3.3uF 16V Electrolytic Capacitor C7 1 1.5uF 16V Electrolytic Capacitor Q1 1 2N2222 NPN Silicon Transistor 2N3904 Q2 1 2N2907 PNP Silicon Transistor Q3 1 NPN Phototransistor D1 1 1N914 Silicon Diode IC1 1 LM308 Op Amp IC IC2 1 LM567 Tone Decoder LED1 1 Infa-Red LED RELAY 1 6 Volt Relay S1 1 SPST Push Button Switch B1 1 3 Volt Battery Two 1.5V batteries in series MISC 1 Board, Sockets For ICs, Knob For R6, Battery Holder RELAY 1 6 Volt Relay

Flash Slave Trigger

Schematic

Parts

Part Total Qty. Description Substitutions R1 1 47K Linear Pot R2, R3 2 3K 1/4W Resistor R4 1 220 Ohm 1/4W Resistor R5 1 680 Ohm 1/4W Resistor C1 1 10uf 25V Electrolytic Capacitor C2 1 0.047uf 25V Ceramic Capacitor Q1 1 2N5777 NPN Darlington Phototransistor Q2, Q3 2 2N3904 NPN Transistor 2N2222 SCR1 1 400V 2A SCR S1 1 1A 120V SPST Switch P1 1 Plug to match jack on slave flash MISC 1 Knob For R1, Wire, Board

Notes

1. Q1 should be aimed at the master flash. R1 should be adjusted for maximum sensitivity but no false triggering.
2. Keep your fingers away from SCR1 when the circuit is operating. It is at 50V-300V and will give you a nasty shock.

Fantastic Atom Expander

Here is the schematic, PC board pattern, and parts placement for a "Fantastic Atom Expander". This circuit produces an "exploding atom" effect using 98 LEDs.

Schematic

PC Board Layout

Parts Placement

Parts

Part Total Qty. Description Substitutions C1 1 0.1uf Mylar Capacitor 0.1uF Ceramic Disc Capacitor IC1 1 4017 IC IC2 1 555 Timer IC L1-L98 98 Jumbo LED (any colour but blue) Q1-Q5 5 2N3904 NPN Transistor R1 1 4.7k Resistor R2 1 680k Resistor R3-R7 4 470 Ohm Resistor MISC 1 PC Board, 9V Battery Snap, IC Sockets Notes The LEDs can be any colour but blue. For a very interesting effect, make one ring red, the next one green, the next one orange, then yellow, etc. The transistors can be most any inexpensive NPN transistor (2N2222, PN2222A, Etc.). For a very interesting (and expensive!) effect, replace the 2N3904's with 2N3055 power transistors on heatsinks and use 12 V 500ma incandescent bulbs instead of LEDs.

Fantastic Atom Expander

Here is the schematic, PC board pattern, and parts placement for a "Fantastic Atom Expander". This circuit produces an "exploding atom" effect using 98 LEDs.

Schematic

PC Board Layout

Parts Placement

Parts

Part Total Qty. Description Substitutions C1 1 0.1uf Mylar Capacitor 0.1uF Ceramic Disc Capacitor IC1 1 4017 IC IC2 1 555 Timer IC L1-L98 98 Jumbo LED (any colour but blue) Q1-Q5 5 2N3904 NPN Transistor R1 1 4.7k Resistor R2 1 680k Resistor R3-R7 4 470 Ohm Resistor MISC 1 PC Board, 9V Battery Snap, IC Sockets Notes The LEDs can be any colour but blue. For a very interesting effect, make one ring red, the next one green, the next one orange, then yellow, etc. The transistors can be most any inexpensive NPN transistor (2N2222, PN2222A, Etc.). For a very interesting (and expensive!) effect, replace the 2N3904's with 2N3055 power transistors on heatsinks and use 12 V 500ma incandescent bulbs instead of LEDs.

Electronic Dice Circuit

Schematic

Parts

Part Total Qty. Description Substitutions R1, R5, R6 3 22K 1/4W Resistor R2 1 10K 1/4W Resistor R3 1 4.7K 1/4W Resistor R4 1 150K 1/4W Resistor R7 - R13 7 330 Ohm 1/4W Resistor C1 1 1uF Electrolytic Capacitor C2 1 4.7uF Electrolytic Capacitor D1 1 1N4148 Signal Diode D2 - D8 7 Red/Green/Yellow LED Q1 1 2N3904 NPN Transistor U1 1 555 Timer IC U2 1 74LS192 4 Bit Counter IC U3 1 74LS08 Quad Intengreted AND Gate IC S1 1 SPST Momentary Pushbutton Switch MISC 1 Board, Wire, Sockets For ICs, Case Notes Pushing and holding S1 causes the LEDs to rapidly cycle. Releasing the button locks the pattern and shows a number from 1 to 6. When building the circuit, make sure to position the LEDs as shown on the schematic. Otherwise the pattern of the dice will look weird. Two circuits can of course be both powered by one switch to make a dual dice.

Colour (Sound) Organ

Schematic

PC Board Layout

Parts Placement

Parts

Part Total Qty. Description Substitutions C1 1 22uf 250V Electrolytic Capacitor C2 1 22uf 250V Electrolytic Capacitor C3 1 0.1uf Disc Capacitor C4 1 0.01uf Disc Capacitor C5 1 0.0047uf Disc Capacitor R1 1 47K 1/2 W Resistor R2, R4 2 6.8K 1/2 W Resistor R3, R5 2 1M 1/2 W Resistor R6 1 3.3K 1/2 W Resistor R7, R8, R9 3 1K 1/2 W Resistor R10, R11, R12 3 10K Pot D1 1 1N4004 Diode Q1, Q2 2 2N3904 NPN Transistor 2N2222 Q3, Q4, Q5 3 106B1 SCR Teccor S2003LS1 T1 1 10K:600 Ohm Audio Transformer S1 1 SPDT Switch J1, J2, J3 3 AC Socket MISC 1 AC Line Cord, Crystal Microphone, Case, Wire Notes R10, R11 and R12 control the response of the different lights. The circuit can handle up to 300 watts per channel. This circuit is NOT isolated from the 115 Volt line. If it is used with the case opened or not installed in a case, you could recieve a bad shock or be killed. You can also use the Teccor S2003LS1 SCR for SCR1. These give better sensitivity and brightness than the 106B1 units. Thanks to James Maloway for redrawing the schematic.

Black Light

This circuit is a simple ultraviolate light that can be powered by a 6 volt battery or power supply (such as the power supply on the"Circuits" page) that is capable of supplying 1 or more amps.

Schematic

PCB Layout and Parts Placement

Parts

Part Total Qty. Description Substitutions C1 1 0.0047uf Mono Capacitor C2 1 0.1uf Disc Capacitor D1, D2 2 1N4007 Diode FTB 1 Filtered Blacklight Tube IC1 1 555 Timer IC P1 1 10k Trim Pot Q1 1 TIP30 PNP Power Transistor R1 1 470 Ohm Resistor R2 1 270 Ohm Resistor S1 1 Slide Switch T1 1 Medium Yellow Inverter Transformer MISC 1 IC Socket, Heat Sink For Q1, Screw, Nut, Wire and PC Board Notes P1 changes brightness of the black light tube. Transformer T1 and the blacklight tube are available from The Electronics Goldmine (see "Where To Get Parts"

Adjustable Strobe Light

Schematic

PC Board Layout

Parts Placement

Parts

Part Total Qty. Description Substitutions R1 1 250 Ohm 10 Watt Resistor R2 1 500K Pot R3 1 680K 1/4 Watt Resistor D1, D2 2 1N4004 Silicon Diode C1, C2 2 22 uF 350V Capacitor C3 1 0.47uF 400 Volt Mylar Capacitor T1 1 4KV Trigger Transformer (see "Notes") L1 1 Flash Tube (see "Notes") L2 1 Neon Bulb Q1 1 106 SCR F1 1 115V 1A Fuse MISC 1 Case, Wire, Line Cord, Knob For R2 Notes T1 and L1 are available from The Electronics Goldmine (see Where To Get Parts). This ciruits is NOT isolated from ground. Use caution when operating without a case. A case is required for normal operation. Do not touch any part of the circuit with the case open or not installed. Most any diodes rated at greater then 250 volts at 1 amp can be used instead of the 1N4004's. Do not operate this circuit at high flash rates for more than about 30 seconds or else C1 and C2 will overheat and explode. There is no on/off switch in the schematic, but you can of course add one.

40W Fluorescent Lamp Inverter

Schematic

Parts

Part Total Qty. Description Substitutions R1 1 180 Ohm 1W Resistor R2 1 47 Ohm 1/4W Resistor R3 1 2.2 Ohm 1W Resistor (only needed once) C1, C2 2 100uF 16V Electrolytic Capacitor C3 1 100nF Ceramic Disc Capacitor Q1 1 TIP 3055 or 2N3055 or equivalent L1 1 See "Notes" T1 1 See "Notes" MISC 1 Wire, Case, Board, Heatsink For Q1, heatshrink, AM antenna rod for coil#

Notes

1. Email Bart Milnes with questions, comments, etc.
2. Wind L1/T1. You will need an AM antenna rod that is about 60mm (2.5 inches) long to wind T1/L1 on. T1/L1 are wound on the same core. Shrink a layer of heatshrink over the core to insulate it. Leave 50mm of wire at each end of the coils.
   Primary: Wind 60 turns of 1mm diameter enamelled copper wire on the first layer and put a layer of heatshrink over it.
   Feedback: Wind 13 turns of 0.4mm enamelled copper wire on the core and then heatshrink over that.
   Secondary: This coil has 450 turns of 0.4mm enamelled copper wire in three layers. Wind one layer and then heatshrink over it. Do the same for the next two.
   
3. Calibrate/test the circuit. To calibrate/set up the circuit connect the 2.2 Ohm 1W resistor (R3) in series with the positive supply. Connect a 40W fluorescent tube to the high voltage ends of the transformer. Momentarily connect power. If the tube doesn't light immediately reverse the connections of L1. If the tube still doesn't work, check all connections. When you get the tube to light remove the 2.2 ohm resistor and the circuit is ready for use. You will not need R3 again.
4. This circuit is designed for 220V lamps. It will work with 120V units just fine, but will shorten the life of the tube.
5. This page has been extensively rewritten by Bart Milne. (15/3/01)