| Whenever an antediluvian electric doorbell is used in an apartment building, the rain of sparks that is generated when the Wagnerian hammer...
Peter Lay (24)
| With just a low cost DC adapter and the circuit described here it is possible to build a low cost stabilised, uninterruptible 9 V supply. On...
| This circuit can precisely measure electrostatic charge. The charge to be measured is stored on C1 (a high quality MKT capacitor with a valu...
| There is no such thing as complete protection against overvoltage damage due to a lightning strike. However, the risk of a valuable piece of...
| The continuity tester is a handy adjunct to an ohmmeter. The unit or component whose continuity is to be checked is connected between term...
| There are many different types of code locks, ranging from numeric keypads through chip cards and magnetic-card readers. The one presented...
| The circuit is intended for carrying out harmless experiments with high-voltage pulses and functions in a similar way as an electrified...
| This article describes an isolating transformer that is, in fact, composed of two standard transformers. Like a much more expensive comme...
| The “chip card” consists of a small board on which an integrated circuit, IC1, forms the key. The logic circuit for the key is hard-wire...
| The continuity tester can distinguish between high-, medium-, and low-resistance connections. When there is a conductance between the in...