I have three K8008 two of which work correctly. The problem one is being used as a non-retriggerable timer. The timer works correctly if only momentary ON connections are made but if the ON connection is sustained the timer does not turn off. The start/stop timer mode has the same problem where the load does not turn off after the timed period if the ON connection is sustained. The other modes of the timer work correctly. IC power supply is 4.95V. Swapping the timer IC for a known good one does not rectify the problem and the IC from the faulty K8008 works correctly in another K8008.
Have you any suggestions as to what is the cause of the problem ? I suspect that the timer is resetting itself at the end of the first timing period - but how could this happen?
Are you using the K8008 together with the K8006?
(K8008 is not intended for stand-almone use, as some of the required circuitry is parts of the K8006 module).
I am using the K8008 alone. What is in the K8006 relavant to my query? Why would two of my K8008 units be OK but the third one not ?
Problem solved !
I am using the K8008 together with the insides of a Mercury remote control switch (BH9938_L) to do remote control switching of the inputs of a Quad 44 pre amp. I am not using the standard K8008 terminal pads and I had inadvertently connected one of the K8008 switch inputs to the base of T1 rather than earth .