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80-470

8 Watt Audio Amplifier

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.
80-525

5 LED Sequential Flasher

 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.
80-570

ION Generator

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.
80-630

One Chip AM Radio

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 two stage, transistor audio amplifier and 3" speaker. Operates from 9 volt battery. A good kit for beginners to see and build.
80-670

DC Motor Speed Controller

 Vary the speed of DC motors the very best way with this kit. Gear boxes 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.
80-680

Variable Power Supply

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 text book 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
80-910

Four Train Sound Effect

Ideal for model railroads; produces the whistle, train chugging sound, crossing bell and the ‘clickety-clack of crossing a bridge.
80-980

MONAURAL PREAMPLIFIER

Our audio amplifier kit works very well, but if your input is a tape head, magnetic phono cartridge or electric mike, the input level may be too low to do the job. This small preamp can be used in these applications; plus, we have included a mike that may be used with the circuit. Power at 6V to 12V (current at 12V is 3mA, only 2mA at 9V). The gain is more than 40 dB.