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n/a
DELETED (Inactive)
26 Posts |
 Posted - Aug 26 2003 : 11:37:58 AM
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i use 4013 connect to a transistor(1815) ,then use 1815 to turn on the relay to control an A.C.
appliance.
i press a button give a clock pulse to 4013,then the output of 4013 is holding in positive voltage,when i give 2nd clock pulse to 4013,the output of it will retun to 0v,this output is connected to the base of 1815,emitter of 1815 is connected to ground voltage,collect of 1815 is connected to one side of the relay coil,the other side of coil connected to +9v,then i give 1st clock pulse to 4013 the relay is turn on,but i give 2nd clock pule to the 4013, the relay cant turn off and it is holding
why ?
thanks
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n/a
DELETED (Inactive)
26 Posts |
Posted - Aug 27 2003 : 11:04:58 AM
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please help
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Aaron Cake
Administrator
Canada
6718 Posts |
Posted - Aug 28 2003 : 09:14:08 AM
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While the relay is "holding", what is the voltage at the base of the transistor? Have you used a series resistor at the base?
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n/a
DELETED (Inactive)
26 Posts |
Posted - Aug 28 2003 : 10:52:03 AM
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i havent use series resistor at the base
do i need to use 2 transistor to control the relay?
thanks
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Aaron Cake
Administrator
Canada
6718 Posts |
Posted - Aug 29 2003 : 3:53:02 PM
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You need a resistor at the base of the transistor to limit current. Start with 1K, and go up from there.
Yes, you need the transistor.
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relay cant unlock?
