Wiring & diagram Info

15 seconds delayed switch-off, A good idea for bedroom lamps
This circuit is intended to let the user turn off a lamp by means of a switch placed far from bed, allowing him enough time to lie down before the lamp really switches off. Obviously, users will be able to find different applications for this circuit in order to suit their needs.

Parts :
R1 = 470R 1/2W
R2 = 100K
R3 = 1M5
R4 = 1K
C1 = 330nF-400V
C2 = 100µF-25V
C3 = 10nF-63V
C4 = 10µF-25V
C5 = 10nF-63V
D1 = 1N4007
D2 = 1N4007
D3 = BZX79C10
D4 = TIC206M
Q1 = BC557
IC1 = 7555 or TS555CN CMos Timer IC
SW1 = SPST Mains suited Switch

Circuit operation:
Due to the low current drawing, the circuit can be supplied from 230Vac mains without a transformer. Supply voltage is reduced to 10Vdc by means of C1 reactance, a two diode rectifier cell D1 & D2 and Zener diode D3. IC1 is a CMos 555 timer wired as a monostable, providing 15 seconds on-time set by R3 & C4. When SW1 is closed, IC1 output (pin 3) is permanently on, driving Triac D4 which in turn feeds the lamp. Opening SW1 operates the monostable and, after 15 seconds, pin 3 of IC1 goes low switching off the lamp.

This software functions as a long period astable mutivibrator. The mark and space period can be set from 1 second up to a maximum 65535 seconds (18h12m15s). Using the internal 4Mhz RC oscillator delays with an accuracy of 99% or better can be achieved The code also implements an edge triggered reset and an active low hold function. The reset edge can be configured for rising or falling edge. The hold function is active low and stretches the timed period for as long as the hold input is held low. In addition to this up to 128 mark/space time pairs can be used which are executed sequentially allowing complex pulse trains to be generated. 

50W Amplifier Circuit, built based ICL8063 as power transsistor driver and 2N3055 as main power amplifier component.

50W Amplifier Circuit based ICL8063 + 2N3055 schematic diagram:


Parts List:

R1 = 200 Ohm R2 = 200K R3 = 30K R5 = 1K R6 = 5K R7, R10 = 1 Meg R8,R9 = 0.4 Ohm/5Watt R11 = 10K Potensiometer R12,R13 = 51K R14 = 47K C1 = 100uF/35V C2 = 0.011uF C3 = 3750pF C4,C6 = 1000pF

C5,C7,C8 = 0.001uF C9 = 50pF C10 = 0.3uF C11,C12 = 10.000uF/50V U1,U2 = 741 Op Amp U3 = ICL8063 Audio Amp Transister Driver Q1 = 2N3055 NPN Power Transistor Q2 = 2N3791 PNP Power Transistor BR1 = 250 V 6 Amp Bridge Rectifier T1 = 50V Center Tapped 5 Amp Transformer S1 = SPST 3 Amp Switch S2 = DPDT Switch F1 = 2 Amp Fuse SPKR1 = 8 Ohm 50W Speaker

Circuit Notes:

• Distortion is much less than 0.1% up to 100HZ and increases to about 1% at 20kHz.
• 50V CT transformer might be difficult to find, you may use 45V or 32V CT transformer.
• Q1 and Q2 should be use heatsinks to prevent over heating.

50W Amplifier Circuit based ICL8063 + 2N3055 source page