Led: Voltage Meter

Schematic for an electronic audio level VU meter that uses LED's to display the volume/audio levels.

This LCD panel meter is a very flexible design that can be customized to your own VOLT meter or AMP meter needs. It may be customized to measure any voltage range, standard or not. Or you can customize it to measure input from a transducer; full details a

This temperature meter uses a Harris 7106 IC as the heart of a low cost, accurate temperature meter. LCD 3-1/2 digit readout. All of the active circuits are in this one, versatile chip. In addition to temperature functions, the board includes an area for

A circuit with 8 LEDs that flash in a somewhat random fashion (well it's not actually at random, but it does visually appear that way).

Circuit diagram for an ultra low-noise driver/supply circuit for white LEDs, using the IC LTC3201. Ensures a stable brightness in white LED driven items.

Flashes five very bright LED's in any one of seven, user-selectable, patterns. A COB (chip-on-board) IC makes assembly very easy; the chip is supplied premounted on its own board and a motherboard contains the entire circuit. Operates on 3 volts DC, batte

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.

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.

The circuit flashes five LED's in sequence repeatedly until you turn it off. Flash rate is user adjustable. The circuit uses an IC chip on Board which you will then mount on the included mother board; battery holder is included. Powered by a 3 volt supply

This LCD panel meter is a very flexible design that can be customized to your own VOLT meter or AMP meter needs. It may be customized to measure any voltage range, standard or not. Or you can customize it to measure input from a transducer; full details a

Using ultrasonic techniques, this solid-state design has no moving parts.

Versatile light organ based on PIC microcontroller.

This is a very eye appealing audio accessory. Displays an approximate output level for each channel of a stereo amplifier. Connects to the speaker terminal; levels are displayed in ten steps. User may select either a moving dot bar appearance. Uses two LM

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.

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

Electronic circuit schematic that works as a Hangman LED game. Fun game to play with a friend, and very educational and entertaining circuit to build.

Schematic for an electronic circuit that behaves as an electronic version of a Roulette wheel. Flashed 10 LEDs in sequence with slowing pace until only 1 remains illuminated.

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 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.

Complete instructions and circuit diagram for a Geiger counter meter device, which will allow you to measure radiation levels.