$14.34

$37.24

$9.52

$36.12

$51.38

$21.72

$50.14

$23.86

$13.96

$21.48

$46.90

$107.40

$163.26

$53.12

$18.68

$14.24

$41.06

$19.46

$17.60

Two separate relays can be switched via encoded signals transmitted from a keychain size, two-button transmitter (like those used for car alarms and electric car doors). Push a button and relay toggles "closed" and one more push toggles it "open". Transmit distance is about 120 feet maximum. The receiver requires from 12 to 15 volts DC. The transmitter is supplied assembled and tested complete with its own battery. Tricky (receiver) parts of the circuit are supplied already assembled and tested; just plug them in and solder in place. Each relay can handle up to 10 amps @ 120V AC; plenty for numerous applications; control lights, door locks, magic shows etc.

$69.46

$30.50

$15.24

$13.96

$15.44

$15.50

$12.18

$13.78

$19.08

$10.50

Only a photo of the PC board was available at press time; but all component parts are included.

A stepper may be used to orient a video camera, antenna, spotlight etc. or used for table position in production. This driver will control a 5, 6 or 8 lead unipolar stepper motor (often available from surplus dealers). The circuit permits fast or slow run rate and even single stepping into final position; uses the UCN5804B IC. Four LED’s indicate movement if motor is remotely controlled (input from 6 to 35 volts). The kit is supplied with quite a bit of good information, how to identify motor connections, spec sheets and a list of references for reading about steppers etc.

$67.86

This is a very simple circuit, generating square waves for use with test equipment, teaching, etc. Generates square waves of approximately 1Hz, 10Hz, 100Hz, 1KHz, 10KHz, & 100KHz. This is a good teaching aid kit, both for the instructor and the DIY user.

$21.72

The kit enables user to control two unipolar stepper motors via the parallel port. Four digital inputs are also included (these may be used  for monitoring external switches, inputs etc.). The kit does not require a power supply. Included, an extended D-shell plastic case (RS-232 style) and all parts. A DOS based program written specifically to drive ‘steppers’ is included on diskette, complete with C source code.

$43.42

$24.74

For the uninitiated, VOX = Voice Activated Switch. This is a switch (relay) that may be activated with any sound, including the human voice. A very sensitive circuit that may be adjusted to react to very low volume sounds or a yell or hand clap. While a VOX is often used to activate a sound recorder, it may be used to trigger an alarm (the mike easily picks up vibrations in windows, wall or door), activate a video camera, radio transmitter or simply turn on a light. The relay will release after a few seconds of silence, holding as long as sound continues. (Hold time may be changed up to 30 seconds) Operates on 12V DC and very low current.

$22.28

$43.42

Turn on any tape recorder that has a remote on/off jack (most cassettes). The circuit has a feed back and delay circuit for robust operation. You could add a relay for switching heavy loads; and tape recorders are not the limit. How about turning on lights via voice or a whistle? Circuit switches off after six seconds of silence.

$20.64

$15.24

$45.18

$41.06

$55.80

40 Second Message Recorder Kit (with looping option)

The circuit uses information Storage Devices Corp. # ISD2540 chip to store one or more audio/voice messages up to forty seconds (maximum time). If desired, the first message can be looped so that it plays repeatedly. Non-volatile; the messages) is/are retained even when the power is removed. Output is to a User- supplied four or eight ohm speaker. The output is small and you may wish to add an LM386 amplifier kit or another amp to increase the volume for your application. The same circuit could be used with any of the ISD25xx chips in the series up to 120 seconds record time. Operates on 6 volts at 100mAmaximum.

$58.58

FM Telephone Transmitter Kit

Miniature transmitter attaches to the phone line and transmits the conversation. Transmits 200 yards and more in most installations. Tunable to clear spot on the FM band of your radio. Completely parasitic; i.e. uses the power from the telephone line and needs no battery. The circuit might be used to share or record conversations, but please do not use illegally.

$15.25

$36.36

$18.76

$46.24

$31.18

OpAmp Function Generator Kit

A very low cost and simple circuit to generate square, pseudo-sine wave and triangular waveforms in the audio frequency range. Uses a quad OpAmp type LM384. This is an educational kit and recommended to instructors and to the person wanting to understand electronics more thoroughly.

$16.14

$17.20

$82.48

$15.36

$15.42

$19.94

Electronic Combination Lock Kit

This really is an excellent introduction to electronic security systems. Set your own four-digit code, a wrong sequence simply resets the lock. The correct code will activate a relay that can handle up to 240 volts AC. The nine-digit keypad is on a separate board connected to the circuit via a ribbon cable (30"), so a variety of mounting ideas is possible. Requires a 9 or 12 volt battery or supply.

$22.78

PIR Movement Detector Kit

One of our favorite circuits. The circuit sees infrared heat, such as from an intruder’s body. The kit uses a late development in movement IC’s and employs a very sophisticated circuit. You may set it to non-trigger in daylight hours. When tripped, an LED indicator lights and relay is tripped. "Sees" up to about eighteen feet. Operation on 9 or 12 volt battery with very long life.

$49.22

9-Volt Siren (loud) Kit

A simple circuit with a lot of output. Uses a voltage controlled oscillator; and includes a 1/2watt speaker. Connect it to an alarm system, sound switch or whatever you dream up. Produces the loud rise-and-fall of typical siren. 9volt battery operation.

$15.24

Two Stage FM Transmitter or Wireless Mike Kit

A powerful little circuit with surprisingly good audio quality. Can transmit up to about 1/2 mile in open country. This is probably the most powerful FM transmitter that you can legally purchase. An electret microphone is used to add sensitivity. The circuit can run on six volts, greatest output is at 12 volts, but use 9 volts and short antenna wire to stay legal.

$14.24

General Purpose 3-1/2 Digit LCD Panel Meter Kit

(Photo shows only the PC board, but parts are included)

A versatile meter, which may be set up for any one of many ranges; for voltage or current. The decimal point is selectable too (i.e. you may put it where you want it). Space is provided on the circuit board for scaling and shunt resistors. Runs on nine volts; very low current drain. Easy to read.

$41.18

5 LED Multi-Sequential Flasher Kit

Flashes five, very bright LED’s in any one of seven, user selectable, patterns. A COB (chip-on board) IC makes assembly very easy; the chip is supplied pre-mounted on its own board and a motherboard contains the entire circuit. Operates on 3 volts DC, battery holder is included. Continuously repeats a sequence when power is applied.

$15.24

8 Watt Audio Amplifier Kit

Low voltage operation does not mean low power. This amplifier can produce a full eight watts into a standard four or eight ohm "load", such as a speaker. Actually, it can deliver up to 11 watts if you use a 16volt supply. You may use this amplifier with a wide range of power supplies, from 5 volts to 20 volts. The IC has built-in current limiting and over-heating protection. An ideal building block for use with many other projects. The audio quality is excellent.

$25.82

5 LED Sequential Flasher Kit

The circuit flashes five LED’s in sequence repeatedly until you turn it off. Flash rate is user adjustable. The circuit uses an IC chip-on board, which you will then mount on the included motherboard; battery holder is included. Powered by a 3 Volt supply or battery; good for a child’s toy or for those "high-tech" looking special effects for stage plays etc.

$15.24

Ion Generator Kit

Are there some healthful positive benefits caused by being in an environment that contains negative or positive ions? Some reports suggest a wide range of benefits. This generator can be set up to generate either negative or positive ions; the builder’s choice. Operation is from 117 Volts AC power line. You will need to find a case or box for the final assembly, about 2" x 4-1/4" and an inch depth; and an AC power cord from an old lamp (or buy new). You can actually feel the flow of ions from the unit.

$25.82

Infrared Toggle Switch Kit

Control about any device using the remote control from just about any TV set. The circuit switches an on-board SPDT relay; turn it on with the remote, and turn it off with another signal. The relay contacts are rated one amp at 125 volts AC. The circuit operates on any DC supply from 8 to 15 volts; use an old calculator supply etc. This circuit can have some very practical applications, such as turning on a light by an invalid. Your imagination is the limit.

$30.50

78XX Regulated Power Supply Kit

This circuit can be made into a regulated power supply for voltages from five volts up to twenty-four volts. The user must add any of the standard 78xx TO-220 positive voltage regulators (7805 or 7806 or etc. thru 7824) and the voltage will equal whichever part you select (the last two digits of the number indicates voltage; 7805 = five volts etc.) You Input AC or DC (unregulated) about three volts greater than desired output voltage; complete instructions included. The 7800 series outputs up to 1 ampere typically. LED indicator and onboard on/off switch. You could use this with a junk box AC or DC power supply or supply your own transformer etc.

$15.24

Movement Detector Parts almost Kit

This is not quite a complete kit; the package contains the three key parts for a PIR detector (personal infrared detector). You get the PCB mounted Fresnel lens, a PIR movement sensor and the Integrated Circuit that we use in the full kit (# 80-300). Included are eight pages of documentation notes and circuits to show you how to proceed.

$29.28

One chip AM Radio Kit

This is a complete AM radio for the standard broadcast band, most of which is on a single IC. Other components, such as the coils and variable capacitor to make a finished radio, are included. The IC is the RF amp, detector and AGC circuitry. The IC’s output drives a 2-stage, transistor audio amplifier and 3" speaker. Operates from 9volt battery. A good kit for beginners to see and build.

$28.16

DC Motor Speed Controller Kit

Vary the speed of DC motors the very best way with this kit. Gearboxes can be costly and series resistors may cause stalling. This circuit delivers the voltage to the motor with pulses and the speed is controlled via pulse width modulation (PWM). The speed control is a potentiometer, for DC motors up to 100 Volts at a maximum of five amps.

$40.06

Variable Power Supply Kit

A very basic power supply that can be adjusted over a range of about 1.5 to 35 volts DC. If you add a heat sink (included), you can run it as "hot" as 2 amps output; otherwise about 60mA @12 volts. This is a textbook circuit using an LM317, which is a 3 terminal regulator in a TO-220 package. Input can be either AC or DC; DC input must be at least 2.5V above the required voltage output. You could use a surplus transformer from 12 volts up for input.

$18.28

$14.78

Programmable Dice Kit

The idea of an electronic dice game of one kind or another is almost as old as glaciers. But this one is very clever and includes software on a floppy (for the IBM PC) plus a huge manual describing how such things work, software for other projects etc. This may be the most educational kit in the line.

$38.22

Parallel Port Relay Board for the IBM PC Kit (software included)

With each advance in personal computers, a surplus of unwanted older machines increases, either at give-away prices or you may have one sitting on a shelf. Thus you can have a low cost, sophisticated "dedicated controller" to turn on or off devices in the home or lab or radio shack etc. The circuit includes eight relays controlled with (included) software for either DOS or Windows 3.1. Connects to the parallel port of any IBM-PC.

$88.46

Three light/dark Activated Relay Kits

This kit is one of our three separate circuits in one; three separate PC boards etc. This one will give you both useful circuits and experience in different approaches, circuit-wise, to doing the same thing; controlling a device with a change to either light or darkness. Each kit is equipped with a relay rated up to 240VAC @ 5 Amps. You may either turn "on" or turn "off" the controlled device. A good kit for the student learning electronics.

$43.04

$58.58

An amplifier designed with portability in mind; ideal for battery applications. A full watt from each channel, excellent fidelity. Uses a Samsung KA2209 IC. Small size: the board is 1-3/8" by 2". All basic parts supplied, including PC board; you supply two 8-ohm speakers. We suggest a 6volt or 9volt battery pack using AA cells; use D cells if extra long battery life is required. Amplify your CD or Walkman or that special project etc.

$19.94

$29.04

The Rohm BA5406 IC is used to make this powerful little stereo amplifier. The entire circuit is on a 1-1/2" x 2-1/2" circuit board. You’ll need to allow added space of 1-1/2" x 1-1/2" x 2-1/2" for the heat sink, plus ventilation for the same. In addition to a 12 VDC power supply (batteries), you will need to provide 4 or 8 ohm speakers, cables and a heat sink compound to put between the IC and the heat sink.

$34.74

$15.24

$35.86

$15.24

If someone put a BUG (listening device) in your meeting room, would you know it? Today’s small circuits make listening devices too easy to conceal or ignore. You may want to assemble this one for resale to nervous and needy users. Even the professional should consider a high quality circuit. It will detect any transmitter