Newest circuit diagrams

Bidirectional Photoelectric System

Detects and counts inputs and outputs. Suited to control Lamps, Household Appliances etc.

Smart Trailing Socket

Mains sockets switched automatically by a Control Socket Up to 1000W switched power

Electronic Door Release

The IC is a quad 2 input "AND" gate, a CMOS 4081. These gates only produce a HIGH output, when BOTH the inputs are HIGH. When the key wired to 'E' is pressed, current through R1 and D1 switchs Q5 on.The relay energises; and Q5 is 'latched on' by R8. Thus, the Alarm is set by pressing a single key,say one of the two non-numeric symbols.

Radio Friendly Power Supply

Power supplies should not create any unwanted interference across the radio spectrum. Switch mode power supplies are one of the strongest sources of interference, and harmonics can be heard throughout long, medium and short wave bands. This power supply, is extremely noise free, and therefore radio friendly. In addition, it has a very high rejection of line frequency and is suitable for powering receivers and small power transmitters.

Push-bike Light

Automatic switch-on when it gets dark. 6V or 3V battery operation

A Bipolar Regenerative Receiver

Schematic for the 530 kHz to 1650 kHz AM Broadcasting Band.

Novel Buzzer

This novel buzzer circuit uses a relay in series with a small audio transformer and speaker.

Voltage Comparator

This circuit will provide an indication whenever the input voltage differs from two defined limits, V1 and V2. The limits are adjustable and the circuit made to trigger from the adjustable "window".

Connection Tester

A low resistance ( 0.25 - 4 ohm) continuity tester for checking soldered joints and connections.

Static Detector Negative Ion Detector

A sensitive detector for static electricity based around a single Field Effect Transistor It can also be used to detect the presence of negative ions, or test a negative ion generator.