Sensor - Circuits - Electronic Blog for hobbyist

Remote Doorbell Warning Switch

The hardest part for this circuit was the title. It is quite easy to miss the sound of a doorbell if you are watching TV ... Read more »

Category: Sensor | Views: 1066

Sound Operated Switch

This sensitive sound operated switch can be used with a dynamic microphone insert as above, or be used with an electret (ECM) microphone. If an ECM is used then R1 (shown dotted) will need to be included. A suitable value would be between 2.2k and 10kohms. ... Read more »

Category: Sensor | Views: 1051

Frost Alarm

The thermistor used has a resistance of 15k at 25 degrees and 45k at 0 degrees celsius. A suitable bead ... Read more »

Category: Sensor | Views: 1029

Infra-Red Remote Control

I have received a number of emails requesting schematics for infa-red remotes. So here is one. This remote transmits a tone using an infa-red LED. This tone is decoded by the receiver. Since the receiver only switches when it "hears" the tone, there are no accidental activations.

Schematic For Transmitter
... Read more »

Category: Sensor | Views: 1073

IR Remote Control Extender Circuit

This is an improved IR remote control extender circuit. It has high noise immunity, is resistant to ambient and reflected light and has an increased range from remote control to the extender circuit of about 7 meters. It should work with any domestic apparatus that use 36-38kHz for the IR carrier frequency. Please note that this is NOT compatible with some satellite receivers that use 115KHz as a carrier frequency. ... Read more »

Category: Sensor | Views: 1166

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	Electro-Hobby	Sunday, 17.11.2024, 13:59
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Schematic For Transmitter ... Read more »

Schematic For Transmitter
... Read more »