Newest circuit diagrams

Fuse Monitor Indicator

The simplicity of this circuit uses just two components, but with just one resistor and an LED this circuit gives visual indication of when a fuse has blown.

Signal Tracer and Injector

A simple test circuit to fault find audio and radio equipment. Can be used to inject a square wave signal, rich in harmonics, or used with headphones as an audio tracer.

Headphone Amplifier

An amplifier to drive low to medium impedance headphones built using discrete components.

Zener Diode Tester

I have teamed up with Magazine Mikro Elektronica for this project. Please visit their site. I am very grateful to Aleksandar Dakic for the kind translation into Serbian and Romanian languages.

IR Remote-Control Checker

Suitable for any Infra-red emitting device, 3V battery supply

Medium Wave Active Antenna

This is a compact three transistor, TRF receiver with fixed feedback. It is similar in principle to the ZN414 which is now replaced by the MK484. The design is simple and sensitivity and selectivity of the receiver are good.

Battery-powered Night Lamp

Ultra-low current drawing 1.5V battery supply

Timed Beeper

Beeps 7.5 seconds after a preset time Adjustable time settings: 15 s. 30 s. 1 min. 2 min. & others

Audio Peak Level Meter

Using a single MOSFET Op-amp this circuit samples the audio input and displays peak readings.

Long delay Timer

This timer was designed mainly to switch off a portable radio after some time: in this way.