Astable/Monostable oscillator using 555 IC

Low current touch switch

Touching the on contacts with a finger brings pin 3 high, turning on the Darlington pair and supplying power to the load (transistor radio etc)

Balanced-modulator

When the carrier level is adequate to switch the cross-coupled pair of differential amplifiers, the modu· lation signal, which has been applied to the gate, will be switched at the carrier rate, between the collector loads. When switching occurs, it will result in the modulation being...

Three Stage Sequential Timer Circuit

By using three 555 ICs, three sequential pulses can be generated.

Capacitance operated battery powered light

Touch the plate and the light will go on and constant of the 47 µf capacitor and the 2M remain on

Closed-loop-tracer

The tracer, consisting of both a transmitter and receiver, is designed to follow a closed-loop wire or cable system. It follows an induced voltage path created by feeding a low-current, audio-frequency signal through the cable. When the pick-up coils come within close proximity of the...

100Mhz-vhf-crystal-oscillator

Diagram shows a 100MHz oscillator operating on the fifth harmonic. Again to maintain the transistor"s gain, note the increase in the collector"s load resistance Rl because of the increase in the quartz crystal"s internal series resistance R5. C3 is needed at frequencies above 50 MHz to tune out...

Negative to positive supply logic level shifter

This simple circuit provides for level shifting from any logic function (such as MOS) operating from minus to ground supply to any logic level (such as TTL) operating from a plus to ground supply

Tone burst generator

The tone burst generator supplies a tone for one-half second after the power supply is activated; its intended use is a communications network alert signal. Cessation of the tone is accomplished at the SCR, which shunts the timing capacitor CI charge current when activated. The SCR is gated on...