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Home Alarm – 2 Sector

The  alarm keeps wailing if the door is kept open. It only turns off after 5-10 minutes when the door is opened and closed. The two door switches trigger the alarm as an Instant or Delayed input and these switches…
Metal Detector

This  Metal detectors will detect ferrous (iron, steel, stainless steel) as well as non-ferrous (copper, tin, gold, lead, silver, aluminium) as well as alloys (brass, cupro-nickel, pewter etc). Depending on the complexity of the circuit, a metal detector will be…
The Capacitor-fed Power Supply

The   capacitor-fed power supply is sometimes referred to as a TRANSFORMERLESS POWER SUPPLY. This article is going to shock you because it is going to tell you all the reasons why you should NOT design, produce or use a CAPACITOR-FED…
LED Tester

This. project is very simple. It is just a 4.5v supply with a LED and resistor in series. When the two probes touch they complete the circuit and the “test LED” (the red LED) will illuminate. When the probes are…
1 watt LED Lamp

This circuit is an extension of the 1-watt LED Driver project. It is a very clever circuit and will illuminate up to six 1-watt LEDs or 30 white LEDs to give an overall illumination of about 1 watt. The 1-watt…
1 watt LED Driver

This circuit will drive a 1 watt LED from 1 or 2 cells (commonly called “dry cells”). The circuit consists of only 4 components plus a LED and the secret to its operation is the transformer. It is operated in…

This circuit provides a visual 9 second delay using a 7 segment digital readout LED. When the switch is closed, the CD4010 up/down counter is preset to 9 and the 555 timer is disabled with the output held high. When…