I am actually pretty green at electronics, but was able to build the below circuit successfully with LOTS of help from people.
The circuit is used to drive a 12V motor bi-directionally to open a chicken coop door; and the Q1 andQ2 transistors are tripped by a 5v input from a MicroController (in this case Webcontrol 8.0).
It is a sort of Flip Flop circuit (as most of you can easily see I'm sure).
It has been running successfully for months, until I had the bright idea of adding 'local (at the coop door) push buttons to over-ride the Q1 and Q2 transistors with a simple button, thinking that would be all I had to do to get local control of the doors (BTW - the 12V circuit is constant ON - only interrupted by the SW1 and SW2 switches - at top and bottom of door).
The lines in blue indicates where I tried 'jumping' the transistors, again, using a simple push button - attaching line to C and E. However, this, after a few tried, fried the transistors.
Do I simply need to add a Diode to stop revere direction, or is my principle of 'jumping' the transistors totally off base?
Any help would be greatly appreciated as I am stuck.
TY!!
Rainer
The circuit is used to drive a 12V motor bi-directionally to open a chicken coop door; and the Q1 andQ2 transistors are tripped by a 5v input from a MicroController (in this case Webcontrol 8.0).
It is a sort of Flip Flop circuit (as most of you can easily see I'm sure).
It has been running successfully for months, until I had the bright idea of adding 'local (at the coop door) push buttons to over-ride the Q1 and Q2 transistors with a simple button, thinking that would be all I had to do to get local control of the doors (BTW - the 12V circuit is constant ON - only interrupted by the SW1 and SW2 switches - at top and bottom of door).
The lines in blue indicates where I tried 'jumping' the transistors, again, using a simple push button - attaching line to C and E. However, this, after a few tried, fried the transistors.
Do I simply need to add a Diode to stop revere direction, or is my principle of 'jumping' the transistors totally off base?
Any help would be greatly appreciated as I am stuck.
TY!!
Rainer