This be the circuit sets the time to model is simple,at can fix the time had long ago and have tall good accuracy. By use pillar equipment be IC CA3140 for fix time mouth and NE555 perform sound electric bell origin. By we can fine time value done to a turn VR1 can fine since 10 second arrive at 3 hour. When the time expires will have an electric bell that a loudspeaker. For the equipment that should choose specially. Be C1 100uF 16V values should are a kind Tantalum. Because tall quality more Electrolytic. The moderately but if no …
This be power supply variable regulator circuit, since 5V to 13V that current about 1A. By use IC LM7805 (3-Terminal 1A Positive Voltage Regulator) perform maintain one’s position voltage, be stable that 5V. And have op-amp IC number CA3140 , help fine decorate voltage go out can modify 5V to 13V from get, by use VR1 in fining decorates. It takes current from output feed come back still a pin GND of LM7805 control the level voltage get efficiently better using resistor R1 only. See little detail in the circuit. Related Links DC power supply LM7805 voltage regulator Variable regulated …
0-30V 5A variable benchtop power supply circuit,Output voltage 0-30V and Current 5A max. Use IC LM723 is a voltage regulator designed primarily for series
This wien bridge oscillator circuit which is normal,low distortion and can easily adjust the resonance frequency that depends on the pair of the resistors (R) and capacitors (C). Which we can calculate by the formula. F = 1/2 p RC In this circuit as Figure 1 the oscillator are based by the R that include with R1 + P1a (or R2 + P1b), and C is C1, C2 or either C3 (or C4, C5 or C6). And more parts are connected with IC1, IC2 op-amp ICs. Figure 1 Schematic diagram of Wien bridge oscillator circuit. The some output signal from …
Sometimes, we need to measure very tiny AC voltage and also high frequency. We cannot use a general meter. How it works This circuit can easily measure the very tiny AC voltage and high frequency 100 Hz to 500 Khz. Use an op-amp is the input is mosfet types, so has input impedance about 10 M ohms. The lowest full scale of this meter is 15 mV on a galvanometer 100uA. A galvanometer is a very sensitive meter to measure tiny currents, usually 1mA or less. It is analog multimeter, cheap and somewhat accurate. Best for observing the trend of …