Four-Hour Timer

The following schematic diagram is four hour timer circuit. Feature : easy to build, 3 hours 53 minutes total time,9V supply voltage. Component : 555 timer IC, Resistor, capacitor, switch, transformer, LED, CD4040B, Relay, BC547 transistor, 1N418 diode, variable resistor. [wiredworld.tripod.com]

Lithium Chargers

This is a lithium charger circuit. Feature : variable current 100mA-2A, simple circuitry, easy to build, inexpensive circuitry, +12V supply voltage. Component : LM741, variable resistor, resistor, zener diode, capacitor, L200. [flyelectric.ukgateway.net]

Bench Amplifier

The following circuit is a bench amplifier. Feature : voltage gain of 200, 325mW of power, simple circuitry, work on 4 to 12Volts DC. Component : capacitor, resistor LM386, switch, variable resistor.[zen22142.zen.co.uk]

MPX4115 Barometric Pressures Circuit Diagram

Barometric Pressures Circuit Diagram

Description: The following circuit shows about MPX4115 Barometric Pressures Circuit Diagram. This circuit based on the MPX4115 IC. Features: bring the voltage down to the active range of 5 volt opamps, output is fed to the 1-Wire DS2438 A/D, available overall gain is about 12.6 (i.e. 0.68 * 2.16 * 8.58), opamp stage with a gain of U1A, capable of a gain range of 1/1 to about 8.58/1, 4.25 to 3.79 volts at sea level, 2.77 to 2.45 volts at 10,000 feet. Component: Resistor, IC, Capacitor, Variable Resistor.[davidbray.org]

1 wire Barometer Using MPX4115

This is a 1 wire barometer using MPX4115 circuit. Feature : Simple circuitry, more reliable, output voltage ranges from about 4.17 to 3.72 volts at sea level, about 3.5 to 3.04 volts at 5000 feet, gain of 4.4. Component : MPX4115, 7805 regulator, DS2438, 1N4001 diode, resistor, capacitor, 2N4403 transistor, LM358 op amp, variable resistor. [davidbray.org]