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hi,mos33
Can you tell more detail about your problems.?
I think If you use that Ic your state of Relay always changes between ON<-> OFF. What exactly do you want to control for which purpose
connect a diode across the relay in reverse bias under normal operation,.... this will take care of the protection.... this diode is called free wheeling diode....
hi all
the problem in details is when i connect the relay to the o/p pin of the 555 time "in monostable connection" normally the led lights for a certain time and be off
but In the presence of the relay it be on always
can u help me??
Seems like you may be pulling current through the relay coil. Are you sure that the led and resistor is across the relay coil and not to another power rail. From memory the 555 will sink up to 200ma, that is to say the relay connects to the output pin and the other end to the + supply. You should connect a diode across the coil with the Cathode (band) to the + side. There is lots of 555 info on the net with circuits if you do a search. Hope this helps.
IF the frequency ON/OFF of 555IC is larger then 24HZ , you can't see led on/off so you can't test the circuit by that way!
Try to hear the sound of relay when Relay stick is on/off sate.
if it was in operation when connected directly then it would be working when connected using relay too... i think current is passing even when the relay is supposed to be off.... please post your circuit and give us a clear insight....
in the figure you have posted the LED glows because the transistor Vbe drop when it is on has to be satisfied by the other path too and the other path contains the LED and hence it glows.... the relay doesn't have these restrictions so please tell how you connected the relay.... a picture with the relay usage would be helpful.... please post it....
i can't understand what u need??
the picture i sent it has all connections including the relay connection.........
the problem now in this picture is when the 555 trigered ,the o/p of it is 5V always
i dont understand how your output can be 5V always because a 1kΩ resistor and the base emitter junction are in series in between the output pin and the ground and since the base current of the transistor will be in µAs the voltage across it be around 2V at the maximum else the transistor will be burnt out.... measure the base current of the transistor and post it please....
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