Wednesday, May 29, 2013
|
Labels:
amps,
audio,
dual,
end,
for,
high,
polarity,
psu,
unregulated
|
|
A power supply suitable for use with the hi-fi amplifiers presented in the predeeding project is perfectly simple, and no great skill is required to build (or design) one. There are a few things one should be careful with, such as the routing of high current leads, but these are easily accomplished. Design of this power supply is very simple. A 4 ampere fuse is used to protect the transformer and two LEDs at the end of this circuit are used to indicate power state On and Off. At the ouptut there are 6 capacitors used you can reduce the quantity of these filter capacitors to 2 or according to your own choice.
click on the images to enlarge
Monday, May 13, 2013
|
Labels:
adaptor,
car,
circuit,
fm,
for,
stereo
|
|
With this compact FM adapter circuit plugged into the audio out of your cassete player or i Pod out put,you can listen your favorite music on your car stereo.This circuit is very useful if your car stereo does not have an auxiliary in socket.The circuit is nothing buy an short range FM transmitter.The FM transmitter circuit is based on low power NPN transistor 2N2222.The tank circuit consisting of L1 & C1 produces the necessary oscillations at the collector of Q1.The capacitance C4 , resistance R3 & R4 performs the function of mixing the stereo out put from the audio player or i-Pod.The emitter resistance R2 provides sufficient stability to the circuit.It also limits the collector current to increase the battery life.
Notes.
* Use a 28SWG , 10 cm insulated copper wire as antenna.
* For L1.make 8 turns of 20 SWG insulated copper wire on a 5mm dia plastic former.
* Power the circuit from a 3V battery.
* Assemble the circuit on a good quality PCB or common board.
* C1 can be a 50pF trimmer.
![](\"http://2.bp.blogspot.com/-3HFvsO7D6yc/TfEoDS_hDhI/AAAAAAAAA8w/bh_epVytgyo/s1600/Extende%2BTimer%2BRange%2Bfor%2Bthe%2B555w.gif\"){kind=link}