50 Watt Amplifie small subwoofer Circuits..

This is a handy, easy to build general purpose 50 watt amp. The amp has an input for a radio, TV, stereo or other line level device. It also has a phono input for a record player, guitar, microphone or other un-amplified source. With the addition of a low pass filter at the input, it makes a great amp for a small subwoofer.

 

Cell Phone and iPod Battery Charger Circuit..

5 band graphic equalizer Circuits

  

Galaxy S3 Audio Problem and solution..

Samsung Galaxy series is known to be one of the finest smart phone ranges that exist today, and this is mainly because its features have surely beaten a good number of industry giants. But nothing is flawless, no matter how better the technology is, as after some time it is going to start having some issues in it due to any of the reasons.

 

Nokia 6270 PCB board layout.

Nokia 6270 PCB board layout
The front and back side layout of components on Nokia 6270 main PCB board. to be used as mobile phone repair manual on Nokia 6270.

SIMPLE 230V LED DRIVER Circuits ..

230V LED Driver circuit without transformer. Here i am using 5 led's you can increase the count at your convineance. Due to the absence of Transformers we can reduce the cost and size of the circuit considerably. As we all know LED's are Cheap, efficient and cool device with low power consumption. So we can reduce our electricity bills to a great extent.

The circuit is powered by 230V 50Hz ac supply, so be careful while troubleshooting this project.

Led's commonly works only in DC, so we have to convert the alternating current to direct current and step down to a safe value before applying to the led sequence.

The circuit mainly consisting of 5 led bulbs, a bridge rectifier and a filtering network with voltage regulator.



The bridge rectifier is used to convert alternating current (AC) to pulsating DC. It is made possible by means of rectifying diodes (D1 to D4 1N4007)


The filtering is made possible by means of a capacitor (47uF). It is used to eliminate the ripples coming from rectifier circuit.

After regulating the filtered voltage using a zener diode, we get an almost direct current suitable for LED's.

230V LED Driver circuit without transformer. Here i am using 5 led's you can increase the count at your convineance. Due to the absence of Transformers we can reduce the cost and size of the circuit considerably. As we all know LED's are Cheap, efficient and cool device with low power consumption. So we can reduce our electricity bills to a great extent.

The circuit is powered by 230V 50Hz ac supply, so be careful while troubleshooting this project.

Led's commonly works only in DC, so we have to convert the alternating current to direct current and step down to a safe value before applying to the led sequence.

The circuit mainly consisting of 5 led bulbs, a bridge rectifier and a filtering network with voltage regulator.



The bridge rectifier is used to convert alternating current (AC) to pulsating DC. It is made possible by means of rectifying diodes (D1 to D4 1N4007)


The filtering is made possible by means of a capacitor (47uF). It is used to eliminate the ripples coming from rectifier circuit.

After regulating the filtered voltage using a zener diode, we get an almost direct current suitable for LED's.
- See more at: http://www.mycircuits9.com/2012/08/230v-led-driver-circuit.html#sthash.zRwA5uPL.dpuf

230V LED Driver circuit without transformer. Here i am using 5 led's you can increase the count at your convineance. Due to the absence of Transformers we can reduce the cost and size of the circuit considerably. As we all know LED's are Cheap, efficient and cool device with low power consumption. So we can reduce our electricity bills to a great extent.

The circuit is powered by 230V 50Hz ac supply, so be careful while troubleshooting this project.

Led's commonly works only in DC, so we have to convert the alternating current to direct current and step down to a safe value before applying to the led sequence.

The circuit mainly consisting of 5 led bulbs, a bridge rectifier and a filtering network with voltage regulator.



The bridge rectifier is used to convert alternating current (AC) to pulsating DC. It is made possible by means of rectifying diodes (D1 to D4 1N4007)


The filtering is made possible by means of a capacitor (47uF). It is used to eliminate the ripples coming from rectifier circuit.

After regulating the filtered voltage using a zener diode, we get an almost direct current suitable for LED's.
- See more at: http://www.mycircuits9.com/2012/08/230v-led-driver-circuit.html#sthash.zRwA5uPL.dpuf

FM-Transmitter Circuit.

Nothing critical here. To get a bit of tuning out of the coil you could put a 4-40pF trimmer capacitor (optional) parallel over the 1 μH coil, L1. C1/C4 and C5/C6 are ceramic capacitors, preferably NPO (low noise) types. C2/C3 are electrolytic or can be tantalum types. The antenna is nothing more than a piece of 12" wire or a piece of piano wire from 6" to 12".

To find the signal on your receiver, make sure there is a signal coming into the microphone, otherwise the circuit won't work. I use an old mechanical alarm clock (you know, with those two large bells on it). I put this clock by the microphone which picks up the loud tick-tock. I'm sure you get the idea... Or you can just lightly tap the microphone while searching for the location of the signal on your receiver.

Parts List

R1,R3 = 100K

R2 = 10K

R4 = 470 ohm

C1,C4 = 470pF

C2,C3 = 4.7μF, 16V, electrolytic

C5,C6 = 4.7pF

C7 = 4-40pF trimmer cap (optional, see text)

L1 = 1μH

Q1,Q2 = 2N2222, NPN transistor

Mic = Electret Microphone

B1 = 9 Volt, Alkaline battery