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 key-pad 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.

No. 80-290 Electronic Combination Lock kit

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

No. 80-310 9-Volt Siren kit

General Purpose, 3-1/2 Digit LCD Panel Meter (PHOTO shows only the PC board, but parts are included. Click photo for larger view.)

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.

No. 80-340 LCD Panel Meter 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. (our 80-065 Varactor tuned unit is considered the best kit of this type. Need a stereo unit? See 80-085)

No. 80-320 Wireless Mike kit

Low Voltage Phone
Recorder Switch (connect to telephone)

The term "low voltage" applies to the tape recorder itself; many tiny recorders operate on very low voltages (as low as 1.5V) and older circuits won’t work with them. This unit will turn "on" any recorder that has a REMOTE and MIC jack for external control. Turns the recorder on when handset is off the hook, off when you hang up.

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 16 volt 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.

No. 80-470 Amplifier 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.

No. 80-375 5 LED 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-onboard 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.

No. 80-525 LED Flasher kit

No electrical connection to the telephone is required, attach a suction cup to the hand set and turn on the amplifier. This project permits group listening to phone calls. Or you can monitor any other oscillating electrical field. Dual IC’s provide a good quality amplifier, the circuit runs on 6 volts DC. Everything is included except the batteries.

No. 80-550 Phone Pickup 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.

 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.

No. 80-580 IR Toggle Switch kit