Serial IO controller & analogue sampler

Looking for an easy-to-drive I/O controller? This unit connects to the serial port of your PC and can be programmed to switch relays, in response to voltage, resistance, temperature and digital inputs. It also includes comprehensive system timers to control the relays and you can set the system up to operate as a PLC-style controller.

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MEDIUM-POWER FM TRANSMITTER

The range of this FM transmitter is around 100 metres at 9V DC supply. The circuit comprises three stages.
The first stage is a microphone preamplifier built around BC548 transistor.

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PhoneFax Missed Call Allert

This device detects an incoming call on your phone or fax and lights an LED and latches on a relay, which you can use to switch on a lamp or horn in another room or your garage.

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2-LINE INTERCOMCUM- TELEPHONE LINE CHANGEOVER CIRCUIT

The circuit presented here can be used for connecting two telephones in parallel and also as a 2-line intercom.

 

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