fuse

Fuse Monitor

When an appliance ceases to operate, there may be various causes for this, one of which is the blowing of the mains fuse. The monitor proposed here contains an LED that lights when that is the case. It is suitable for use with fuses rated from mili-amperes to amperes. As long as the fuse is[…]

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Voltage Inverter

Voltage Inverter

A negative supply voltage may be obtained with the use of a special inverter IC. but such ICs are not always readily available. Fortunately. if the current drawn is not excessive, a standard HC-MOS chip may be used. The present circuit is based on Type 74HC14, which contains six Schmitt triggers, whose combined gates can[…]

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Scanner for Preamplifier

Scanner for Preamplifier

The scanner is an extension for 0 1 1 the ‘All-solid-state preamplifier’ published in Elektor Electronics* As its name implies, it scans all inputs of the preamplifier to ascertain where there is an audio signal present. That input re-mains selected. After there has been no signal for some time, scanning is resumed. The scanning action[…]

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