That might be my oversight. You should connect the center connection to either one of the remaining terminals. Some VR comes with that done and have only two connections.Two questions. First if I am reading the diagram correctly the varpot the center connection is not used, only the connections across the resistor right?
You only need to change the values of VR(R3) or the capacitor(C8) or both. There is an online webpage that helps to calculate the timing.Second, how easily could I increase the variable delay if I wanted to have a 10 second to 60 second delay? Would this require only a different pot or would other components need to be changed?
You cannot eliminate the limit switches. You cannot depends on how long the motor is running to calculate if the end stops are reached. This will only work if the motor can be stalled when it reaches the end. I'll give an example.First, can the circuit be designed to eliminate the need for limit switches? I would like to be able to set the motor run time in a similar fashion to the adjustable time delay.
I do not understand your concern regarding limit switches.If I do need to use limit switches could I use spst or would I need spdt wired like a 3 way light switch? I am having difficulty finding limit switches with momentary contacts. Thanks again for your help.
Joe
The assumption is correct. The contact of a limit switch only closes when the switch lever is depressed but returns to open if the lever is released.Perhaps I misunderstand the function of spst vs momentary in regard to a limit switdch. I assume the contacts of a spst momentary switch are only closed while the lever is depressed against the stop, and open when released.
Only very special types of limit switch will latch after operation. Most ordinary limit switches will reset, unlike a light switch.If the switch is spst don't the contacts close and latch until the lever is depressed again, just like a light switch, or do all spst limit switches have momentary contacts?