Low: Voltage Relay

There are many applications where you need quick availability of a relay for connection to a particular piece of apparatus. We found in developing our kits that we always needed to have a relay mounted on a PCB within arms reach.

Use an old PC as a "dedicated controller" to turn on or off devices lab or radio shack. The circuit includes eight relays controlled with (included) software for either DOS or Windows 3.1. The kit is a boon to the Science Fair project, laborator

Use an old PC as a dedicated controller to turn on or off devices lab or radio shack. The circuit includes eight relays controlled with (included) software for either DOS or Windows 3.1. The kit is a boon to the Science Fair project, laboratory experiment

You can program this stand alone controller via PC Serial Port. Simply connect a serial cable from your computer to the connector on relay board.

You can program this stand alone controller via PC Serial Port. Simply connect a serial cable from your computer to the connector on relay board.

Low cost 12 channel Infrared Remote Control with relay board

A very simple variable power supply with a DC output voltage adjustable from 1-3- Volts, with a maximum DC current of 5 Amps. Uses LM338 DC voltage regulator IC.

Timer circuits are handy for many experimenters projects, not to mention the photo lab. This kit has three separate circuits that can be used individually or together. Each circuit has a separate 5 Amp relay. Circuits operate on 9 Volt DC.

Data sheet for the 7805 (LM7805), a compact IC 5v DC voltage regulator integrated circuit. This page further describes the 7805 and provides Datasheets for the IC device.

This mini-VOX - voice operated relay - is based on a circuit published in Silicon Chip, 9/1994, p31.

The primary function of this Relay Board is to turn devices on or off. It's simple!

The most powerful circuit we've seen that operates on such low voltage (just two AA cells). A range of 100 meters can be expected and, given a good antenna and FM receiver, 500 meters can be expected. An external power supply can be used up to 9 volts. Tr

An extremely simple and cheap DC power supply with variable voltage (1.2-25 Volts) control. The circuit uses an LM317 integrated voltage regulator Ic.

4 Channel RF Remote Control Relay Board with Auto Roll

The most popular use for this kit is to make you own night-light. It can also be used to switch just about any appliance on or off in light or darkness. Light sensitivity is adjustable over quite a range. The relay can handle up to 10 Amps at 110VAC. Oper

Both a touch and a contact switch are built on one PC board so that the builder can see how each works. A battery can power the contact switch but you'll need an AC power supply for the touch switch to work well. The circuit switches a relay with a 3 Amp

The most powerful circuit we've seen that operates on such low voltage (just two AA cells). A range of 100 meters can be expected and, given a good antenna and FM receiver, 500 meters can be expected. An external power supply can be used up to 9 volts. Tr

Adjust the sensitivity of this circuit to control a Relay that can turn on whatever is connected to the contacts of the relay. Very practical circuit for a variety of projects. Turn on a light when your dog barks, or set of a siren when an intruder makes

This is a low cost 4 digit presettable down counter with output and reset. The count input can be used for both low and high speed applications.

The circuit uses a matched pair of 40 Khz transducer elements to detect movement up to 22 feet away. You may add a relay (not included) to switch higher voltage loads. The unit switches a LED for movement indication. Sensitivity is setable via control. Cr

Variable-voltage DC power supply circuit. The output DC voltage is adjustable from 0.7-24V, with current limiting range from 50mA up to 2 Amps. Main transistor is the 2N3055.