A photo of the Revision-A preamp is shown below. You’ll see that there are two dual opamps, but the schematic only shows one. This is the main part of the Rev-A update – the output section now has gain (which is easily selected), and a better buffered low output impedance. The remainder of the circuit [...]
120 VAC Lamp Dimmer The full wave phase control circuit below was found in a RCA power circuits book from 1969. The load is placed in series with the AC line and the four diodes provide a full wave rectified voltage to the anode of a SCR. Two small signal transistors are connected in a [...]
2 Way Cross-Over 3500 Hz (bass and treble) This is 2 way cross-over for your speaker system. This circuit will handle 2 speaker that are woofer (low frequency) an tweeter (high frequency). The result will shown as below picture: Here the schematic diagram of the circuit:
Temperature Monitor with IC LM741 or LM301 Using a thermistor in the position shown makes a heat activated sensor. A change in temperature will alter the output of the opamp and energize the relay and light the LED. Swapping the position of the thermistor and 47k resistor makes a cold or frost alarm. Temperature Monitor [...]
LM317T Voltage Regulator with Pass Transistor The LM317T output current can be increased by using an additional power transistor to share a portion of the total current. The amount of current sharing is established with a resistor placed in series with the 317 input and a resistor placed in series with the emitter of the [...]
This simple inverter. The main aim of this circuit is to provide a suitable supply for all kind of low power battery chargers that normally connect to the mains such as mobile phones, electric shavers, etc, even an electronic neon light rated at 5W was successfully connected. Only easily obtainable components are used. http://www.circuits-lab.com/
Make a sound card is no more a complex issue. If you use great IC PCM2702 from BURR BROWN / Texas Instruments you can create a fully functional USB sound card. This sound card can be powered from USB port and has one stereo output. You don’t need to install any driver for Windows XP [...]
