Setting Up a 12V DC Test Stand w/ Controller & Cycle Count

[Zarathuztra]

Setting up a test stand that will need a controller to cycles a device ON and OFF at an adjustable time interval (allows me to make the ON duration and OFF duration whatever I want). It will also need to keep a count, so I can track the cycles count and also set a limit on cycles so it will stop when it reaches a certain cycle count. Tests will go normally for 10k+ cycles, but some could go over 50k cycles.

12VDC battery supply is going to go into the controller and it will be powering a 12VDC coil.

I've been trying to google but my result continuously land me to software/computer testing stuff.. Looking for some advice of recommended equipment or setups to handle the requirements. Or at least a company or website that can be a solid resource to figuring out what I need to make the controller.

Voltage: 12V DC battery
Current Max: 6A
Power Max: 70W
Frequency of cycling: likely ON/OFF 2 times a minute at the most, usually slow than that. shortest duration will be ON part of the cycles and that should be a 4 seconds at minimum.

The controller will only be controlling (1) device.

 

[anorlunda]

How much current how many watts are you switching on/off?

How many on/off cycles per second?

How many devices are you switching?

 

[Zarathuztra]

@anorlunda : I've edited the OP to include responses to your questions.

Current Max: 6A
Power Max: 70W
Frequency of cycling: likely ON/OFF 2 times a minute at the most, usually slow than that. shortest duration will be ON part of the cycles and that should be a 4 seconds at minimum.

The controller will only be controlling (1) device.

 

[JBA]

You might take a look at the one below I found by searching "electronic timers" to see if it meets your requirements

http://store.flw.com/products/atc-r...MI69GQxLOm2gIVBmSGCh1jcwVREAQYBCABEgLPMPD_BwE

 

[Asymptotic]

Does the device under test present a purely resistive load, or is it inductive?

Keep a close eye on the output ratings of prospective devices. It may be difficult to find a timer relay with contacts capable of handling 6 amps DC inductive, in which case the solution is to use the timer circuit to drive an appropriately rated power relay.

Thirty years ago what you've described would possibly have been built with (2) 'on delay' timer relays, a counter, and (depending upon load characteristics) a power relay.

1. TMR1 defined the 'dwell' time. Upon timeout it turned on a power relay connected to the load , and started TMR2.
2. TMR2 defined the 'on' time. Upon timeout, it incremented a counter, and opened the TMR1 coil circuit. When TMR1 dropped out so would TMR2, and began the next cycle.

Cycle time = dwell time + on time.

3. The counter would be wired to turn on a "test completed" pilot lamp, buzzer (or whatever was appropriate), and disable timer cycling after it reached count setpoint.

Several manufacturers wrapped up the TMR1/TMR2 action described above into a single, specialized timer relay featuring separately adjustable 'dwell' and 'on' times.

These days, for traditional circuits that required more than two or three discrete devices it usually costs less to use a programmable relay - also known as a 'smart' relay - along the lines of a Siemens Logo! (which I'm mentioning due to having prior experience; there are others). You can download a demo version of their Comfortsoft software which is fully functional except for upload/download capability. $250 USD buys a starter kit including fully functioning software, power supply, and 12/24 VDC controller via Allied Electronics https://www.alliedelec.com/siemens-6ed1057-3ba00-0aa8/70426747/

 

[Zarathuztra]

@Asymptotic mptotic Thanks for the info. I checked Allied Electronics and it looks like they may have what I'm looking for. I'll see if they have an applications engineer available to pick a suitable option.