Elektor Team (9503)

1-07-1983 | LJ doorbel) memory On occasion it may be useful to know when a visitor has called in your absence. This is especially true in the case of an...

1-07-1983 | elektor july/august 1983 capacitance meter In this capacitance m eter, the value of a capacitor is determined by giving it the same charge a...

1-07-1983 | 10 electronic tuning fork A standard tuning fork produces a tone of 440 Hz, that is, the inter- national A (orchestral pitch). It is not ver...

1-07-1983 | 11 noise and vibration detector Whether it is the hi-fi next door, the cat purring quietly, or a knock at the door, the detector described h...

1-07-1983 | elektor july/august 1983 1 car PDM amplifier T This power amplifier, designed for use in a car, delivers 10 W into 4 S2 and because it uses...

1-07-1983 | 13 Iogarithmic amplifier The performance of the operational amplifier, the circuit diagram of which is shown in figure 1, is best seen from...

1-07-1983 | elektor july/august 1983 14 reproducible delay There are many occasions when a switching delay is required. One way of achieving this is to...

1-07-1983 | 15 stable zener As everybody knows the voltage drop across a zener diode is depen- dent on the current passing through the diode. Therefore,...

1-07-1983 | 16 R. Storn symmetrical voltages from a doorbel) transformer This circuit is of interest not merely because it uses a belt transformer with...

1-07-1983 | 17 LED current source If an LED is used in a circuit, the current for that LED is normally set with a limiting resistor. The LED can then be...