Mini Guitar/Bass Amplifier

  Comments: Tiny, portable Guitar Amplifiers are useful for practice on the go and in bedroom/living room environment. Usually, they can be...

Sound Modifier

  Comments: Compared to common Fuzz-box devices, the Sound Modifier circuit allows a choice amongst a wide variety of output waveforms, tha...

Cheap Pump Controller

This simple but effective circuit can be used to control water level in a container. The prototype is used to pump water out of a bucket tha...

Full-duplex Intercom

Comments: This design allows to operate two intercom stations leaving the operator free of using his/her hands in some other occupation, thu...

Speech Amplifier Box

Comments: This circuit is intended to be placed in the same box containing the loudspeaker, forming a compact microphone amplifier prim...

Non-Contact Power Monitor

Here is a simple non-contact AC power monitor for home appliances and laboratory equipment that should remain continuously switched-on. A ...

Circuit Board Tester

  Comments: This little circuit indicates the basic integrity of a printed board, detecting 0V, positive supply voltage from less than 3V t...

E-B-C Transistor Pin Identifier

  Circuit operation: A three-phase wave form is derived from the 350Hz ring-of-three oscillator formed by IC1A, IC1B and IC1C, and applied ...