This is a 2 LED flashing circuit. It is based on an analog flip flop circuit. This particular circuit was calculated to use blue or white 3V LED with a 12V power supply. If you are using red green or yellow LED, replace the 1K resistors for a 2.2K. This circuit will flash the led [...]

Very important: Use the proper wattage (See Schematic) for the resistors. The circuit was calculated to have the maximum LED brightness with minimum heat from the 12K resistor. With a “12Kohm / 2W” flame proof resistor. It will be slightly warm to the touch.

This is circuit MOSFET power amplifier OCL, Output 100w , use mosfet k134+j49 or Mosfet J162 + K1058 Output 112W at Speaker 8 OHM. Power Supply +56V/-56V 4A /Ch.

Voice manipulation device specially intended for props 9V Battery operation. Parts: P1______________10K Log. Potentiometer R1,R10__________10K 1/4W Resistors R2_______________1K 1/4W Resistor R3______________50K 1/2W Trimmer Cermet or Carbon R4,R6,R7,R14___100K 1/4W Resistors R5______________47K 1/4W Resistor R8______________68K 1/4W Resistor R9_______________2K2 1/2W Trimmer Cermet or Carbon R11_____________33K 1/4W Resistor R12_____________18K 1/4W Resistor R13_____________15K 1/4W Resistor C1,C2,C3,C8,C9_100nF 63V Polyester Capacitors C4______________10µF [...]

Three LEDs signal bumper-barrier distance Infra-red operation, indoor use. Parts: R1_____________10K 1/4W Resistor R2,R5,R6,R9_____1K 1/4W Resistors R3_____________33R 1/4W Resistor R4,R11__________1M 1/4W Resistors R7______________4K7 1/4W Resistor R8______________1K5 1/4W Resistor R10,R12-R14_____1K 1/4W Resistors C1,C4___________1µF 63V Electrolytic or Polyester Capacitors C2_____________47pF 63V Ceramic Capacitor C3,C5_________100µF 25V Electrolytic Capacitors D1_____________Infra-red LED D2_____________Infra-red Photo Diode (see Notes) D3,D4________1N4148 75V 150mA [...]

The schematic shown below measures capacitance from 2.2pF to 1000pF in the L (low) range, and from 1000pF to 2.2uF in the H (high) range. ICD of the 74HC132 (pin 11) produces a 300 Hz square-wave clock. On the rising edge CX rapidly charges through D1. On the falling edge CX slowly discharges through R5 [...]

This is an simple and cheap circuit to convert voltage from 12V to 3V.In fact this is a basic regulator circuit.The output voltage determined by Vout = Vzener – Vbe When Vzener is zener voltage output. Vbe is saturate voltage when transistor on (about 0.6V)

R1-15-16-21-22-17-18=1Kohm R33=68ohm 5W Q1-2=BC550C R2=47Kohm R35-36=6.8ohm 1W Q3-4=BC560C R3-4=10Mohm TR1=1Kohm trimmer Q5=BC560C R5-6-13-14=1.2Kohm TR2=1Mohm trimmer Q6=BC550C R7-12=47ohm C1=2.2uF 63-100V MKT Q7-11=BD140 R8-9-10-11=22ohm C2=1nF 100V MKT Q8-9-10=BD139 R19=82ohm C3-4=2.7nF 100V MKT Q12=IRF9540 R20=22Kohm C5=330pF Q13=IRF540 R23-26=56ohm C6-7=100uF 16V F1-2=Fuse 2.5A Fast R24=2.2Kohm C8=1uF 100V MKT L1=see text R25=560ohm C9-11-12=100nF 100V MKT J1= 2pin connector 2.54mm step [...]