I have NO electronics knowledge to the level to build anything. I can solder. I have a project in that I need a timer that I can set to turn ON and OFF for a set amount of time between 1 second and 5 minutes and then be capable of repeating the same operation at a defined time.
I have been looking for a straight forward plug-in digital timer but have not been able to find one that the on/off setting is less than one minute.
The specific use for this time is to open and close a Chicken Coop door at programmed times.
I have AC available but I'm not adverse to DC applications.
If anyone has any suggestions on existing products, kits or can provide instructions on building a timer I would really appreciate the input.
A mechanical timer would be great except they are limited to five minute intervals. Some go as low as one minute limit but I need a capability of adjusting the on/off time in seconds.
Example: I need to turn a motor on for 10-20 seconds and then off. Then I need it to turn on again eight hours later again for 10 - 20 seconds.
The ideal would be to have two seperate switches or relays acting independantly. The first activated with in the defined time and then the second activation on a seperate relay altogether.
In that case the electronics is the way to go. Is a stupid question: have you any friend or somebody with electronics knowedge? I mean, to avoid exposing you to dangerous voltages/currents, he/she can take the schematic to real world
I can locate someone if need be. I can solder and have experience with voltages; I just don't know anything about designing anything. I know that if you touch a capacitor on a large farm motor you better get ready to dance...
I have soldered circuit boards together before and they even worked! I'm just not savvy enough to understand the circuitry without explanation. I was hoping there would be a ready made plug-in digital timer out there but I can't find any that have minimum settings of 0 seconds on...
If the circuitry isn't that complicated and I can buy the parts at Radio Shack I am probably up to it with guidance.
My intention was to use a 3.5v electric screwdriver as my motor. I wanted to turn it on until the door opens and then off. At a specific time I wanted to turn on the motor on in reverse until the door closes and then off. I don't want to rely on sensors on the door as a coop gets really dirty. I just wanted to be able to adjust the on time to how ever long it takes the motor to open or shut the door.
If the timer is a single output on/off then I will use a cam of some sort to open and close the door as it cycles between open and close times.
you won't need a timer for that function at all. Use a switch, two relays and two limit switches to drive, reverse and stop the motor.
Using a timer will be too inaccurate to have the motor stop in time, when the door reaches its maximum open and closed position.
Also a geared electric motor will have different rpm values depending on temperature, meaning you'd have to adjust for summer and winter time at least.
Here is a simple circuit including a PCB layout for your application. The LEDs indicate either door closed or open position. They extinguish when the door is travelling.