P
prizark
Hi guys,
I am using the CD4017 Johnson decade counter in on of my
experiments.I want to turn the relay on during the 4th to 6th clock
pulses of the counting.So I used an OR gate to input the "output 4",
"output 5" and "output 6" of the 4017 to drive the realy from there.
The OR gate is made by using DL(Diode Logic) just a couple of zener
diodes and a pulldown resistor. I know that the output driving current
of the CD4017 is not more than 9mA but it is sufficient to drive and
transistor into saturation and switch on the relay. But for some
reason that is not happening. The circuit is able to drive LED's with
and without transistor at the output but not the relay.The relay is a
6V/100 Ohms type.I even tried using a Darlington pair and also the
intergrated version of the Darlington pair(ULN2803) but couldn't make
things any better. What could be the problem.
Thankx,
prizark.
I am using the CD4017 Johnson decade counter in on of my
experiments.I want to turn the relay on during the 4th to 6th clock
pulses of the counting.So I used an OR gate to input the "output 4",
"output 5" and "output 6" of the 4017 to drive the realy from there.
The OR gate is made by using DL(Diode Logic) just a couple of zener
diodes and a pulldown resistor. I know that the output driving current
of the CD4017 is not more than 9mA but it is sufficient to drive and
transistor into saturation and switch on the relay. But for some
reason that is not happening. The circuit is able to drive LED's with
and without transistor at the output but not the relay.The relay is a
6V/100 Ohms type.I even tried using a Darlington pair and also the
intergrated version of the Darlington pair(ULN2803) but couldn't make
things any better. What could be the problem.
Thankx,
prizark.