Wednesday, November 19, 2014
Battery Charger based on AVR ATMega 8535

Wednesday, September 3, 2014
Simple ON OFF Touch Switch with 555 Schematic
555 ON/OFF Touch Switch Schematic
Parts List
R1 = R2 = 3.3M
R3 = 10K
R4 = 1K
C1 = 10nF
D1 = 1N4007
Q1 = BC547
IC = NE555
12V relay
Tuesday, April 9, 2013
555 Timer Circuit With Variable On Off Times
This circuit enables the on/off times of a 555 timer to be independently varied over a wide range. This is not possible with a conventional 555 circuit with the RC network being charged from the positive supply rail and discharged via pin 7. Instead, the capacitor at pins 2 & 6 of IC1 is charged and discharged from the output at pin 3. Furthermore, the charging and discharging circuits are different, being isolated by diodes D1 & D2.
Circuit diagram:
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555 Timer Circuit Diagram With Variable On/Off Times
Therefore the capacitor at pins 2 & 6 is charged via diode D2 and trimpot VR2 and discharged via D1 and trimpot VR1. With this arrangement you can have very long on times combined with very short off times and vice versa, or you can adjust the duty cycle to exactly 50% and so on. This circuit also employs a second 555 timer (IC2) as an inverter so that complementary pulses are available, if required. If not, delete IC2.
Author: A. Davies - Copyright: Silicon Chip Electronics
Friday, April 5, 2013
Battery Charger based on AVR ATMega 8535
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Function-Based Battery Charger Part Series AVR ATMega 8535 With LCD Display
