Electronic Reversing Circuit for Model Rains

Many model train enthusiastic UV find the mechanical reversing system for trains in the HO series from Marklin and other manufacturers primitive and unreliable. The system is based on a.c. motors and a mechanical reversing assembly operated by a small electromagnet. The motor speed is determined by the track voltage, which can lie between 4[…]

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4th order single chip filter

High-order filters are normally designed by using two or more 2nd-order sections in series. That means that a 4th-order filter needs at least two opamps. The present filter, however, uses only one opamp, which results in smaller distortion, intermodulation, and so on. Also, there is no internal resonance rise, which typifies combinations of 2nd-order sections.[…]

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REF200 from Burr-Brown

Burr-Brown’s REF200 provides in independent 8-pin DIL package two independent current sources, either of which can supply 100 NA and a 1:1 current. mirror. The pinout of the device is shown in Fig. 1. Note that there are no pins for connecting a supply voltage. The correct operation of the current. sources are, however, guaranteed[…]

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Crowbar Protection

Quite a few electronic components. particularly active ones. cannot withstand too high voltages. Preventing costly circuits dying a premature death because the supply voltage has risen too high makes overvoltage protector no luxury. Such a protector must, of course, act swiftly, otherwise, the deed has been done before it had a chance to act. Therefore.[…]

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Zener Diode Circuits & Applications

– a compact note or tutorial that covers the requisites of Zener diode or voltage reference diode applied in various PSU (power supply units) and other circuits. Zener diodes have diversity of uses in various circuits. The most trivial Zener diode is that when it is applied like a voltage reference component. Among the diversity[…]

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