Electronic Circuit Project » Circuit http://www.electronic-project-circuit.com For Electronic Hobbyist, Engineer, And Student Sun, 26 Sep 2010 14:24:43 +0000 http://wordpress.org/?v=715 en hourly 1 220 Volts Flashing Lamps http://www.electronic-project-circuit.com/220-volts-flashing-lamps/ http://www.electronic-project-circuit.com/220-volts-flashing-lamps/#comments Wed, 02 Dec 2009 04:16:17 +0000 admin http://www.electronic-project-circuit.com/?p=36 This circuit is intended as a reliable replacement to thermally-activated switches used for Christmas tree lamp-flashing. The device formed by Q1, Q2 and related resistors triggers the SCR. Timing is provided by R1,R2 & C1. To change flashing frequency don’t modify R1 and R2 values: set C1 value from 100 to 2200uF instead.

Best performances are obtained with C1=470 or 1000uF and R4=12K or 10K. Due to low consumption of normal 10 or 20 lamp series-loops intended for Christmas trees (60mA @ 220V typical for a 20 lamp series-loop), very small and cheap SCR devices can be used, e.g. C106D1 (400V 3.2A) or TICP106D (400V 2A), this last and the suggested P0102D devices having TO92 case.

220 Volts Flashing Lamps schematic

Parts:

R1___________100K 1/4W Resistor
R2,R5__________1K 1/4W Resistors
R3,R6________470R 1/4W Resistors
R4____________12K 1/4W Resistor

C1__________1000uF 25V Electrolytic Capacitor

D1-D4_______1N4007 1000V 1A Diodes
D5__________P0102D 400V 800mA SCR

Q1___________BC327 45V 800mA PNP Transistor
Q2___________BC337 45V 800mA NPN Transistor

PL1__________Male Mains plug

SK1__________Female Mains socket

Important Note:
For proper operation it’s absolutely necessary to employ high Gate-sensitive SCRs.
If you are unable to find these devices you can use Triacs instead. In this case the circuit operates also with relatively powerful devices. A recommended Triac type is the ubiquitous TIC206M (600V 4A) but many others can work.
Note that in spite of the Triac, diode bridge D1-D4 is in any case necessary.

source : redcircuits.com

]]> http://www.electronic-project-circuit.com/220-volts-flashing-lamps/feed/ 0 Simple High Quality 18W Audio Amplifier http://www.electronic-project-circuit.com/simple-high-quality-18w-audio-amplifier/ http://www.electronic-project-circuit.com/simple-high-quality-18w-audio-amplifier/#comments Thu, 11 Jun 2009 01:29:36 +0000 admin http://www.electronic-project-circuit.com/?p=10 This Audio amplifier has output 18 Watt RMS into 8 Ohm (1KHz sine wave) and Frequency response 30Hz to 20KHz -1dB. It’s simple to build and you don’t need preamplifier. Few notes about this circuit.

  • Do not exceed 23 + 23V supply.
  • Can be directly connected to CD players, tuners and tape recorders.
  • D1 must be in thermal contact with Q1.
  • Quiescent current (best measured with an Avo-meter in series with Q3 Emitter) is not critical.
  • Q3 and Q4 must be mounted on heatsink.
  • To facilitate quiescent current setting add R8 (optional).
  • Adjust R3 to read a current between 20 to 30 mA with no input signal.
  • A correct grounding is very important to eliminate hum and ground loops. Connect to the same point the ground sides of J1, P1, C2, C3 & C4. Connect C6 to the output ground.
  • Then connect separately the input and output grounds to the power supply ground.


Circuit 18W Audio Amplifier

simple 18Watt audio amplifier

Amplifier parts:

P1_____________22K Log. Potentiometer (Dual-gang for stereo)

R1______________1K 1/4W Resistor
R2______________4K7 1/4W Resistor
R3____________100R 1/4W Resistor
R4______________4K7 1/4W Resistor
R5_____________82K 1/4W Resistor
R6_____________10R 1/2W Resistor
R7_______________R22 4W Resistor (wirewound)
R8______________1K 1/2W Trimmer Cermet (optional)

C1____________470nF 63V Polyester Capacitor
C2,C5_________100µF 3V Tantalum bead Capacitors
C3,C4_________470µF 25V Electrolytic Capacitors
C6____________100nF 63V Polyester Capacitor

D1___________1N4148 75V 150mA Diode

IC1________TLE2141C Low noise, high voltage, high slew-rate Op-amp

Q1____________BC182 50V 100mA NPN Transistor
Q2____________BC212 50V 100mA PNP Transistor
Q3___________TIP42A 60V 6A PNP Transistor
Q4___________TIP41A 60V 6A NPN Transistor

J1______________RCA audio input socket

Power supply parts:

R9______________2K2 1/4W Resistor

C7,C8________4700µF 25V Electrolytic Capacitors

D2_____________100V 4A Diode bridge
D3_____________5mm. Red LED

T1_____________220V Primary, 15 + 15V Secondary, 50VA Mains transformer

PL1____________Male Mains plug

SW1____________SPST Mains switch

source : http://www.redcircuits.com//Page1.htm

]]> http://www.electronic-project-circuit.com/simple-high-quality-18w-audio-amplifier/feed/ 0 Circuit Reverse Polarity Protection http://www.electronic-project-circuit.com/circuit-reverse-polarity-protection/ http://www.electronic-project-circuit.com/circuit-reverse-polarity-protection/#comments Mon, 23 Mar 2009 05:10:30 +0000 admin http://electronic-project-circuit.com/?p=5 Circuit Protection

Protection in electronic circuits is crusial factor. especially polarity reverse protection. Can you imagine what happen if our circuit not pretected to reverse polarity supply. All digital IC will be damage, and also electrolit capacitor will blow up. via circuit electronic

]]> http://www.electronic-project-circuit.com/circuit-reverse-polarity-protection/feed/ 0 Simple RF Transmitter http://www.electronic-project-circuit.com/simple-rf-transmitter/ http://www.electronic-project-circuit.com/simple-rf-transmitter/#comments Mon, 23 Mar 2009 05:05:22 +0000 admin http://electronic-project-circuit.com/?p=3 RF Transmitter

This is may be the simplest radio transmitter that you will find anywhere. lt has a total of fiye parts and can be constructed into a very small space. It is great for science fair projects or other science related projects where short range transmission is useful. via electronic circuit

]]> http://www.electronic-project-circuit.com/simple-rf-transmitter/feed/ 0