Most National Health Departments and Councils seem to agree that the recommended fridge temperature should be between 2 °C and 7 °C (35 °F to 44 °F). The lower the temperature, the slower th... Read more
This circuit is a modified version of the circuit found at [1]. The purpose of the circuit is to ensure that AC power is not supplied to devices connected to K3 unless the device connected t... Read more
A noise generator with a wideband output signal is always handy to have around when you’re adjusting receivers and other types of HF equipment. The noise generator circuit described here use... Read more
For many years the author has been approached by people who have managed to lay hands on an ‘antique’ electric clock and need an alternating polarity pulse driver. This is immediately follow... Read more
More and more electronic devices are portable and run off batteries. It is no surprise, then, that so many flat batteries find their way into the bin — and often far too early. When a set of... Read more
The EDE1144 Keypad Encoder IC from E•Lab Digital Engineering (www.elabinc.com) is designed to interface a matrix-type 4 row × 4 column (16-key or less) keypad to a microcontroller or other h... Read more
This circuit is purposely presented with many loose ends (not literally, of course) to stimulate experimenting with RF circuitry at a small outlay. Looking at the circuit diagram you may rec... Read more
It normally takes two transistors to build a blinker circuit (in order to make positive feedback possible). However, you can also use a photoresistor (LDR) that is illuminated by an LED. The... Read more
Unplugging or re-connecting equipment to the serial COM or PS2 connector always gives problems if the PC is running. Even if you only need to swap a mouse or changeover from a graphics keybo... Read more
This circuit is a video line driver specifically intended for use with a single-ended power supply. As a matter of fact, the synchronized outputs of a line driver for composite-video signals... Read more
