Hi, I have built a timer circuit that I found on the web. I am quite new to electronics, and
it wouldn't surprise me if I have made a mistake in producing the pcb.
The timer is needed to shut off an 18v dc charge to a 14.4v drill battery at approx 2 hours.
The strange thing is, this schematic works when tested with the livewire simulation program.
But doesn't work on my etched pcb.
I added a 7812 regulator to drop the voltage from 18v to 12v for the relay coil and 4060b
their is 12v present on pin 12 of the 4060b but nothing happens e:g no leds light ect.
I have also tried various 4060b's and various bc547's in case they were faulty.
I also looked for broken tracks or shorts on the pcb, but all seems OK.
I have adjusted the 470k pot , still nothing happens.
the yellow led should light at 28 seconds to give a 2 hour period before pin 1 of ic energizes the relay to shut off the 18v charge. The green led should flash to indicated the count sequence. I have attached the schematic , and my pcb layout , and my pcb foil side for some one to kindly inspect, and maybe spot an error that I have possibly made.
Thanks in advance for any help offered.
it wouldn't surprise me if I have made a mistake in producing the pcb.
The timer is needed to shut off an 18v dc charge to a 14.4v drill battery at approx 2 hours.
The strange thing is, this schematic works when tested with the livewire simulation program.
But doesn't work on my etched pcb.
I added a 7812 regulator to drop the voltage from 18v to 12v for the relay coil and 4060b
their is 12v present on pin 12 of the 4060b but nothing happens e:g no leds light ect.
I have also tried various 4060b's and various bc547's in case they were faulty.
I also looked for broken tracks or shorts on the pcb, but all seems OK.
I have adjusted the 470k pot , still nothing happens.
the yellow led should light at 28 seconds to give a 2 hour period before pin 1 of ic energizes the relay to shut off the 18v charge. The green led should flash to indicated the count sequence. I have attached the schematic , and my pcb layout , and my pcb foil side for some one to kindly inspect, and maybe spot an error that I have possibly made.
Thanks in advance for any help offered.