Low: Voltage Switch

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

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.

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.

Three relay-based electronic switching circuits that switch according to light levels.

Power on/off almost anything with this infrared controlled electronic switch. Some spell it Infared!

This super cool circuit behaves as a clapper-switch. You clap and the circuit turns on. Clap and it turns off. Great as a light clap switch.

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

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.

This is a basic low cost counter module. Two or more may be plugged together with 6-pin sockets and harness provided. Excellent use as event counter. Has a single 3-digit display. Uses the 14553 and 14551 chips. Has count and reset switches with debounce

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

The TX25 from Broadcast Warehouse is an extremely high quality stereo FM transmitter that complies with FCC Standards, meaning that it can be used for commerical broadcasting. Output power is 25 Watts.

The TX50 from Broadcast Warehouse is an extremely high quality stereo FM transmitter that complies with FCC Standards, meaning that it can be used for commerical broadcasting. Output power is 50 Watts.

The TX300 from Broadcast Warehouse is an extremely high quality stereo FM transmitter that complies with FCC Standards, meaning that it can be used for commerical broadcasting. Output power is 300 Watts.

The TX5 from Broadcast Warehouse is an extremely high quality stereo FM transmitter that complies with FCC Standards, meaning that it can be used for commerical broadcasting. Output power is 5 Watts.

The TX150 from Broadcast Warehouse is an extremely high quality stereo FM transmitter that complies with FCC Standards, meaning that it can be used for commerical broadcasting. Output power is 150 Watts.

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 circuit is an alarm for the home, car and a lot more. It employs a magnet and reed switch to trigger the circuit. An intergral piezo sounder produces the alarm sound (100dB). There is also a relay capable fo handling up to 10 amps that will switch wh

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.

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.

Introduces the Optocoupler-triac MOC3010. Complete electrical isolation between input audio signal (low voltage circuit) and output light modulation. Operates from 100 VAC line. Audio input via 3.5mm jack.