I am having Weird problem for driving a Buzzer in my circuit !!
I want to implement a RF controlled buzzer (i.e. when remote button is pressed, Buzzer should turn on, & it should turn off when remote button is released)
But in my circuit Buzzer is not switching off once it is turned ON !! My circuit description is given bellow !!! PLEASE HELP !!!!
I am using following circuit with modification to drive Buzzer(using transistor) from RF receiver (Decoder HT12D)
in my circuit R16 is 1Kohm , Q4 is BC547, VCC is 5V !!
I am using this RF module :
**broken link removed**
& RF decoder circuit is like this :
**broken link removed**
Rosc in my circuit is 33K !
D8(pin 10) from this circuit is connected to R16(1K) from Above circuit (First one)
^ Yes !! It stops after disconnecting R16 (i.e. removing base drive of transistor physically !)
& I have checked my decoder output after without transistor ! Its also working properly (i.e. 5V & 0V respectively with ON/OFF Button position of remote ) !!
what is the source and sink currents? post data sheet...
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When the output in the wrong case(Buzzing in low input), you tried removing R16 and got buzzer stoped but what is the voltage at the D8 pin after open and before open??
IC HT12D Typical Source & sink currents are 1.6mA !!
Datasheet :-http://www.botskool.com/downloads/electronics/datasheets/HT12D.pdf
When the output in the wrong case(Buzzing in low input):
voltage at D8 pin Before R16 open :- 3.25V
voltage at D8 pin After R16 open :- 0V
Currently in my circuit, i have shorted Vcc of IC HT12D & Vcc of transistor-buzzer circuit to same 5V battery !!
BUT I just noticed that ,,If i supply transistor-Buzzer circuit with another 5V battery It works like charm !!But i dont want to use another battery ,,i want to run whole circuit from the same battery !! WHat should I do ?? please refer following for understanding :-