12: Volt Dc 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.

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.

A very basic power supply that can be adjusted over a range of about 1.5 to 35 volts DC. If you add a heat sink (included), you can run it as hot as 2 Amps output; otherwise about 60 mA @ 12 volts. This is a text book circuit using an LM317, which is a 3

A very basic power supply that can be adjusted over a range of about 1.5 to 35 volts DC. If you add a heat sink (included), you can run it as hot as 2 Amps output; otherwise about 60 mA @ 12 volts. This is a text book circuit using an LM317, which is a 3

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.

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.

Provides 3 amps current at 3-30 Volts DC. Reduces ripple voltage to almost non-existant.

A low power consumption circuit that uses few components in order to power a 6 inch fluorescent tube (AC) from 12 Volts DC.

Build this educational Deluxe Bench DC Power Supply Kit

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

Low cost 12 channel Infrared Remote Control with relay board

Build this educational Deluxe Bench DC Power Supply Kit

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

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.

Vary the speed of your DC motor with this inexpensive circuit. Gear boxes can be costly and series resistors may cause stalling. This circuit delivers the voltage to the motor with pulses and the speed is controlled via pulse width modulation (PWM). The s

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

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

Easy to build sound effect generator kits, inludes several different sounds and tunes.

Timer kits are an ever popular item with the hobbyist. This uses a 555 timer IC and goes from 8 seconds to 8192 seconds.