Basic low cost counter. Two or more counter modules may be plugged together with 6-pin sockets & harness provided. Uses a single-unit 3-digit LED display. Built around the 14553 & 14551 chips. Box & battery provided. The separate COUNTER MODULE shows how to use the Kit as a counter. Has COUNT & RESET switches with debounce circuit built in to eliminate problems from noisy switches. 9V battery operation.

Introduces 3-1/2 digit LCD and the very popular 7106 IC. This IC has been used in low-cost multimeters for over 13 years. We use it to measure temperature using an ordinary signal transistor as the sensor. Data sheets provided. Breadboard area so you can extend the circuit to build your own voltmeter, ammeter, resistance meter or extended-range temperature meter. Takes away the mystery of how multimeters work. Box provided. 9V battery operation.

A kit to introduce you to electronics and circuit analysis. Seven LEDs arranged like a real dice face. Push the switch and the dice rolls then slows down. Ingenious circuit design used to minimize components. Uses 14017 & 555. Box included. 9V battery operation.

Batteries soon become an expensive way to power your electronic kit and electronic games. This is a basic power supply using two 7805 regulators. Input up to 20V AC from a transformer or power pack. Two regulated outputsfixed 5V, the other variable. Box provided. Good introduction to electronics.

A game of skill to turn on the Stairway of 6 LEDs as the bi-color LED flashes. Introduces you to several electronics basic circuits with a surprisingly difficult game to play. Box included. Good introduction to electronics. 9V battery.

Electronic game. Ten LEDs in a circle. One LED is turned on at a time to simulate the spinning of a roulette ball around the wheel. Uses voltage controlled oscillator circuit. 'Ball' gradually slows down and stops on a number. 'Ball' speed can be adjusted. Uses 9V battery.

The most powerful 'bug' available for its size, 3v supply and number of components. Guaranteed to transmit over 100 meters within buildings and to 500 meters in the open. Easily tunable in the FM band. Greater range at higher voltage and better aerial.

Detects very small amounts of light and sounds the piezo alarm. Put it in your cash box or cupboard. Uses Darlington photo transistor MEL12 and 14011 IC. Educational kit.

A learning module. Build and experiment with the Astable, Monostable and RS flip-flop Multivibrators on the one PCB. 6 LEDs & 9V battery powered. See and understand exactly how each works. Good introduction to electronics.

Both types of switch are built onto the one PCB so you can see and explore how each type works. A battery can power the touch switch (2 contacts) but a main power supply (like DIY Kit 4) must be used for the touch plate (1 terminal) to work. High quality 12V relay rated at switching 240V/3A supplied. Uses 14011 IC.

Most ICs operate in the 4V to 40V range. The LM3909 from National Semiconductor changed this. Two PCBs supplied. A 1.5V D cell will flash an LED for over two years. Use as an imitation car alarm. A second PCB connects the chip as a 1.5V continuity tester. Seven pages of documentation provided from National Semiconductor.

Introduces the Optocoupler-triac MOC3010 and triac. Complete electrical isolation between input audio signal (low voltage circuit) and output light modulation (main supply voltage levels) is achieved.

Can be adjusted to turn on your tape recorder through its REMOTE plug. Has feedback and delay circuit for robust operation. Very sensitive. Proven circuit. Needs 6V plug pack for most stable operation.

Miniature transmitter which attaches in series to one of the two lines to your telephone. Transmits over 200 meters to an ordinary FM receiver. Transmits further if the FM receiver is near the phone line. Tune with ceramic trim cap. Uses the phone line as an aerial and power source. Not for illegal use.

This Kit is designed as a building block in other projects where a battery powered, variable gain audio amplifier is required. Data sheet from National Semiconductor included.

More powerful FM transmitter 'bug' than Kit 7. Tank oscillator coil built into the circuit board. Can be tuned anywhere in FM band. 9V battery operation. Over 400m range in the open depending on aerial used.

2 boards; one with matched pair of ultrasonic transducers to detect motion from 4-7m away. 2nd board contains Xtal controlled osc. & all circuits. Switchable latch, red LED indicator. Solder pad output to drive external relay or circuits. Runs on 9V battery. Main board: 2-3/4"x2"x3/4", Transducer board: 2-3/4"x5/8"x7/8".

Simple two wire intercom. Each unit with its own speaker, microphone and amplifier (LM386). Can be modified to a hard wire 'bug'. With 4 strand ribbon cable the power to bug can be sent to the remote 'bug' unit from the receiving unit.

9V battery powered xenon tune flasher. Transformer supplied. Wire is pre-wound on the bobbin, but you must do the final winding of two outer coils. Full instructions provided. Trim pot to vary flash rate. Useful & educational.

Cheap and simple circuit to generate square, (pseudo) sine and triangle waveforms in the audio range. Uses quad op amp LM348.

This is the most important piece of equipment for test-ing and measuring digital equipment. It is usually used in fault finding and testing, but can also assist in design work and to find out how digital equipment works. Switch for either TTL or CMOS. Our own modern design using a PUT. Includes detection circuit for very fast pulses. Gives visual (3 LED's) and audio (piezo buzzer) response.

Allows you to send sound through plastic 1mm fiber optic cable. Matched transmitter/receiver pair from Motorola. Two circuit boards with a microphone at one end and a speaker at the other. 14 feet fiber optic cable supplied. Will work over 200 meters.

A 1W power amplifier building block designed to be part of a larger project needing a low power battery operated operation into an 8 ohm speaker.

A sound activated switch and a FM transmitter joined together to make a sound activated FM Tx. Set the level of sound that it will respond to. Two stage transmitter needs tuning to get best results. Tuning Kit & instructions enclosed. Tranmits up to a Km in the open depending on the aerial used.

An introduction to a basic but fully working combination lock. Separate touch pad with 9 pads. Lock is reset if an incorrect digit is pressed. Relay capable of switching 240V supplied. 12V operation. Robust and versatile.

A surprisingly loud siren for such a simple circuit. Uses voltage controlled oscillator. Half watt, 8 ohm speaker supplied. 9V operation. Ideal to attach to an alarm system which needs a sound module.

Our most powerful FM 'bug' to date. A two stage FM transmitter with an RF transistor (2N3563 or ZTX320) in its output stage. 9V operation. On/off switch mounted on the PCB.

KIT 15 was designed to switch on a standard 6V tape recorder when the phone was used. This is a redesign using an FET to switch low voltage tape recorders as low as 1.5V. Tape recorder will turn on when the phone is used. Plugs into REMOTE & MIC jacks of recorder.

Make this general design 3-1/2 digit LCD panel meter into your own voltage or current meter. Or custom make it to measure input from a transducer. Full details given in the documentation. LCD may be cut from the main circuit board and mounted separately.

Replace your expensive 9V battery by one or two more cost-efficient 1.5V cells. Uses Texas Instruments TL496 IC. Jumper switches between 1 or 2 cell operation. Battery holders for 1 & 2 x 1.5V cells included.

General Purpose 4-1/2 Digit Counter uses Harris 7224 IC. Full instructions INCLUDING the 7224 data sheet is included. All pins from the 7224 are brought out for easy access. Directly drives an LCD (provided). This project is a building block that you can use as part of a larger project. The LCD section can be cut away and connected by a flat ribbon cable. The Kit has its own 5V regulated supply on board for the 7224, allowing a relatively wide range of voltage inputs from +6V to 10V. The Harris 7224 counts up to 15MHz, guaranteed, 25MHz typical.

Learn to program microcontrollers without going to technical college. This Kit introduces the Motorola 68HC705K1, an 8 bit, 16-pin microcontroller released in 1992. The Kit is a down counter from 60 or 90 seconds with beeps every 10 seconds. All the software code is supplied and fully explained. See how easy it is to change the time and beep settings by simple changes in the software program. You can judge for yourself how using micro-controllers is a huge advance over using logic ICs. On/off switch and pulldown resistors on input lines are all built into the K1 and are under software control. 9V battery powered.

All the information about how to continue learning to program these "computers-on-a-chip" is supplied. The tools to program the K1 are available at very low cost (under $200) from Motorola. The K1 is the simplest 8-bit microcontroller available.

Complete kit to make a 2-way FO audio link. Full duplex, 2 PCBs. 14ft. FO cable supplied. 12-15V AC/DC input. Call button. Add more cable using FO connector supplied.

Accurate reaction times to the nearest milli-second are shown for one or two players. Random beep sounds in a 4 second interval. Best ever reaction time stored in RAM. No cheating allowed! Crystal controlled. All software code provided with comments & flow charts. Uses 8 pin Motorola 68HC705K1.

Teach yourself how to convert binary into decimal, hexadecimal & 2's complement hex and decimal. Just 2 ICs. Uses Motorola K1 microcontroller. All code supplied on disk. Counts up or down, slow or fast.

There are many applications where you quickly need a relay for a project. This kit is a 12V relay which will switch 120VAC at 5A or 240VAC at 2A. Relay outputs are brought out to terminal blocks. Diode to overcome back-emf from relay coil discharge included on the PCB.

We have added a transistor switch to Kit 43. A positive signal over 2.5V will turn the transistor & the relay on. Zero signal to turn it off. Signal inputs & relay outputs are brought to terminal blocks. Diode to short the back-emf from the relay coil. LED indicates when switch is on.

There are many applications where you quickly need a relay for a project. This Kit contains two 12V miniature relays which will switch 120VAC at 1A. All relay outputs are brought out to terminal blocks. Diode to overcome back-emf from relay coil discharge included on the PCB.

Learn the basic topics of audio power amplification - boot strapping, cross over distortion, complementary pairs, push pull - by building this Class A & AB power amplifier. Full explanation.

Our second movement detector. 40kHz crystal locked circuit. Will reliably detect movement 4m to 7m away. Use 9V to 12V. Ideal for monitoring door opening or movement passed a point. Full circuit description. LED indicates movement. Signal Out provided so you can add your own alarm circuit or relay.

5 LEDS flash on and off in sequence after a switch is closed. The flashing sequence will remain on until the switch is closed again. 3V operation. Uses small chip on board PCB. Adjust the flash rate by changing the external resistor value. Spare COB PCB provided.

Door relay, 2nd relay & alarm relay, EPROM data storage. Many features, easy to use. Commented source code provided on floppy disk.

Microcontroller based. Seven timing modes, up to 18.2 hours in 1 second steps. Input & reset can be switches or isolated electrical input. All commented code on disk so you can teach yourself to program.

We supply all the components & double sided PCB to make a P9 programmer. Top quality components including 2 ZIF sockets & 4 C&K switches. Requires 12V regulated input.

Universal PCB to take any TO-220 3 terminal positive regulated IC (user supplied). Unregulated AC or DC input via terminal block or power jack. Off/on switch. LED indicator. A quick and neat way to provide a positive, regulated voltage to a project.

We supply the 3 essential components to make your own PIR movement detector. A PIR sensor, PCB-mounted Fresnel lens plus the latest movement detector IC. 8 pages of application notes show you how.

An AM radio all on one PCB. Uses a tuned radio frequency front end, AM radio IC and 2 amplification stages. All components including speaker provided. Full explanation.

To Order,

Please Call Toll Free at (800) 811-5208

Inside the Phoenix-Metro Area Please Call (602) 464-2485

©1995 Circuit Specialists, Inc.