This circuit gives out an alarm when its sensor is wetted by water. A 555 astable multivibrator is used here which gives a tone of about 1kHz upon detecting water. The sensor when wetted by water completes the circuit and makes the 555 oscillate at about 1kHz. The sensor is also shown in the circuit [...]

This circuit will allow you to place a phone call on hold and if you wish to have them listen to music while they are on hold. The circuit operates as follows: The RED wire from the phone jack is typically positive and the GREEN wire is negative or ground. When you want to place [...]

All resistors are 1/4W.The circuit is powered by 9…15V DC or AC. When In Circuit Programming (ISP) connectors are used, is possible the programmer to be powered from target’s power source. Diodes D2 and D6 protect the regulator LM7805, when target’s power is used. ‘ XTAL JUMP ‘ is used to cut XTAL when the [...]

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Circuit High power supply regulater 0-30V 20A by LM338 This is High current and Adjustable Volt 0 to 30V 20A. It easy circuit and nice circuit, Because use IC LM338 and IC 741. Volt Output adj by VR1-1K. IC LM338 to hold heat-sink. Transformer is 20A up.

Componets R1 = 180 KOhm C1, 6 = 10uF/16V TR1, 2, 3 = BC547 , BC548 R2 = 12 KOhm C2 = 47uF/16V P1 = 10 KOhm trimmer R3, 8 = 47 KOhm C3 = 4,7 pF P2 = 47 KOhm trimmer R4 = 3,9 KOhm C4, 7 = 1 nF IC1, 2 = 741 [...]

R1a = 2,2 K R1b =470 Ohm R2 = 10 K R3, R7 = 3.3 k R4 = 390 Ohm R5 = 47 K R6 = 3.3 K 1Watt R8 = 180 Ohm R9, R10 = 0.47 Ohm 3Watt R11 = 0.075 Ohm 2Watt R12 = 470 Ohm P1 = 500K liner potentiometer P2 = [...]