Hello everybody,

one of the forum members gave me this forums name to become a member. He thinks it will be helpfull for some of You having difficulties putting together an electronic device of a german kit concerning the language. I will be glad to help everybody out with translations and if necessary illustrations.

Just let me introduce to You briefly. I am Hans, a retired GAF captain, having flown all kinds of aircraft for 23 years, last RF4-E Phantom. Since I handled my aircraft allright it always handled me right and I had no accident during my flying time.

I have a problem concerning a timer schematic. That is what it is supposed to do:

Count up and down, must be presettable for up and down count and stop counting after the preset time has elapsed thereby triggering a sound signal and a relay. I've got the schematic so far to count up using  M74HC190 and the appropriate BDC to 7-segment decoder and LED driver but I have no idea about the "count down" part and how to switch back and forth. May be somebody has the circuit in his drawer and can help me.

Thank You all for Your attention

Kind regards