I need a one shot relay

[overdriv]

Can someone recommend a timing relay for 125VAC that will give me a one shot closure of the contacts for a couple of seconds and then open?

I want to put a counter on my Taco switching relay. I want to know how many times my system runs per day. I have the 125VAC counter but I don't want it to stay energized as long as the system runs. All it needs is a pulse.

 

[mrb]

places like factorymation have them but expect to pay in the mid $30s. do you have any electronics / soldering skills? this is something you can make in 30 min or so with <$5 in parts plus a repurposed wall transformer for the power supply.

 

[Grumpy365]

How are you wiring it?

Do you have a extra pole or aux switch on your switching relay?

If you just installed a pulse counter like this
http://www.kele.com/workarea/downloadasset.aspx?id=9733
Why do you need anything else?

It should count every tine your switching relay makes.

 

[ddawg16]

What is a "Taco Switching Relay"? Does it make Tacos?

The guys pretty much covered it.....if it was me, I would be installing an Allen Bradly PLC along with a PanelView touchscreen.....

 

[cnc-me]

How about a PIC Microcontroller, with a web page so we all can see the usage.

 

[Norcal]

What is a "Taco Switching Relay"? Does it make Tacos?

The guys pretty much covered it.....if it was me, I would be installing an Allen Bradly PLC along with a PanelView touchscreen.....

I assume for a Taco circulating pump.

 

[overdriv]

My, aren't we all sharp this morning.

No PLC, etc.

See attachment for an image of a Taco switching relay, which runs my circulating pump, but does not make tacos.

The part from Omron would be OK but I'd need a socket and a place to put it. Advice and instruction would be needed.

I have basic electronic skills and I can solder.

Grumpy, will that pulse counter stay energized as long as the pump runs? Will it tolerate that?

Sorry for my ignorance guys.

 

[Grumpy365]

What is a "Taco Switching Relay"? Does it make Tacos?

The guys pretty much covered it.....if it was me, I would be installing an Allen Bradly PLC along with a PanelView touchscreen.....

You should definitely move to the PanelView Plus so you can trend when it engages.

 

[Grumpy365]

A counter should count one time every time a switch makes.
A timer will run the duration of the time the switch is made.

Are wires run to all the terminals. If you have a NO (normally open) contact and the associated common terminal not in use, you are golden.

To check you want to ohm thru the contacts, ( you should get nothing) when it is engaged, you should show continuity.


If you are considering the KELE device, call them. They have super good customer service. If the sales guy doesn't know he will put you on the phone with an engineer who knows their product line.

 

[mrb]

ooh ooh this looks fun. Tell you what: ill make you a counter with an LED display but you have to post pictures of it. Am I correct that the control transformer on that thing is 24vac? You are not using terminals 5/6 right?

 

[Joe92GT]

ooh ooh this looks fun. Tell you what: ill make you a counter with an LED display but you have to post pictures of it. Am I correct that the control transformer on that thing is 24vac? You are not using terminals 5/6 right?

http://www.dentinstruments.com/smart_logger_meters_energy_electricity_metering.htm

This might be a bit more than you want to spend, but it does exactly what you want, complete with time stamps. It sits on an electric motor, and you set it to pick up the induction from the motor running. No wires, just Velcro.

The software then downloads all the readings, and charts on, off times, duty cycle, ect. They are also available for lights, current, ect. Very simple units.

We have used these on a heater to determine run time differences based on programmable thermostat settings, and calculate theoretical oil usage based on jet size and pressure.

You can email them, or I can get you a quote if you like. I believe the units are around 100, and I need to see what our cost for the software is. We don't sell to many of these, but customers that use them love them. Also, you can move it to AC compressor or fan during the summer.

Joe

 

[overdriv]

A counter should count one time every time a switch makes.
A timer will run the duration of the time the switch is made.

Are wires run to all the terminals. If you have a NO (normally open) contact and the associated common terminal not in use, you are golden.

That's what I thought too. The counter I have will pull the number half way and hold it there till the contacts on the relay open, then the number will finish rotating. I don't think the counter I have is made to have power on it for a length of time it takes my system to run. Either it or the relay chatters after a bit, because the counter read "21" after about 12 hours. No way did the system run 21 times.

I do have it connected to a NO contact.


Joe and Mrb,
The transformer is 24Vac. I had the counter on 6NO and N, with a jumper from 3 to 5. See this link for more info.http://www.pexheat.com/Catalog/Electronic-Controls/SR501

Mrb are you serious about your offer?

 

[overdriv]

http://www.dentinstruments.com/smart_logger_meters_energy_electricity_metering.htm

This might be a bit more than you want to spend, but it does exactly what you want, complete with time stamps. It sits on an electric motor, and you set it to pick up the induction from the motor running. No wires, just Velcro.

The software then downloads all the readings, and charts on, off times, duty cycle, ect. They are also available for lights, current, ect. Very simple units.

We have used these on a heater to determine run time differences based on programmable thermostat settings, and calculate theoretical oil usage based on jet size and pressure.

You can email them, or I can get you a quote if you like. I believe the units are around 100, and I need to see what our cost for the software is. We don't sell to many of these, but customers that use them love them. Also, you can move it to AC compressor or fan during the summer.

Joe

Although it is a bit more than I need, it would be interesting and fun to have, I might be interested in something like that. If you could price it for me I'd appreciate it. Thanks.

 

[mrb]

That's what I thought too. The counter I have will pull the number half way and hold it there till the contacts on the relay open, then the number will finish rotating. I don't think the counter I have is made to have power on it for a length of time it takes my system to run. Either it or the relay chatters after a bit, because the counter read "21" after about 12 hours. No way did the system run 21 times.

I do have it connected to a NO contact.


Joe and Mrb,
The transformer is 24Vac. See attachment for info.
I had the counter on 6NO and N, with a jumper from 3 to 5.

Mrb are you serious about your offer?

sure. you will need to solder a pair of wires to the secondary of the transformer to get us 24vac for the circuit (which will have rectifier and voltage regulator to get the needed operating voltage).

terminals 4 are connected to whatever this relay switches, and 5/6 are available for the counter right? you would remove your jumper from 3 to 5 as the counter circuit just needs a contact closure, not 120vac.

is a 6 digit LED display going to show a high enough count? there will be a reset jumper you can connect to zero the count so you can play with it then zero it before starting operation.

this will be a PCB (hand made so not the prettiest thing ever, but more than good enough) it will have screw terminals for your wire connections, you will have to fashion a housing for it (ill look to see if i have anything laying around)

 

[overdriv]

sure. you will need to solder a pair of wires to the secondary of the transformer to get us 24vac for the circuit (which will have rectifier and voltage regulator to get the needed operating voltage).

terminals 4 are connected to whatever this relay switches, and 5/6 are available for the counter right? you would remove your jumper from 3 to 5 as the counter circuit just needs a contact closure, not 120vac.

is a 6 digit LED display going to show a high enough count? there will be a reset jumper you can connect to zero the count so you can play with it then zero it before starting operation.

this will be a PCB (hand made so not the prettiest thing ever, but more than good enough) it will have screw terminals for your wire connections, you will have to fashion a housing for it (ill look to see if i have anything laying around)

Sounds doable on my end. 6 digits are plenty. Would the PCB be small enough to mount inside the Taco enclosure? There is some room to spare.

Thank you! PM me the cost and I'll get you the money.

 

[mrb]

Sounds doable on my end. 6 digits are plenty. Would the PCB be small enough to mount inside the Taco enclosure? There is some room to spare.

Thank you! PM me the cost and I'll get you the money.

dont count on it fitting inside the taco enclosure. best for it to live in its own enclosure, i might have something to put it in.

as far as cost, i dont expect to be paid -its sort of a science project for me. maybe ill have you cover shipping cost, we'll figure it out later im not concerned about $ on this.

 

[klhitman]

we use idec at work all the time for a one shot that last a min. but you can set at any time you want.

http://us.idec.com/Product/Family/RTE_Series/RTE-B2AF20.aspx

but you will need a base for it. i love them. so much stuff you can do with it.

 

[overdriv]

we use idec at work all the time for a one shot that last a min. but you can set at any time you want.

http://us.idec.com/Product/Family/RTE_Series/RTE-B2AF20.aspx

but you will need a base for it. i love them. so much stuff you can do with it.

What would something like that cost, with base?

 

[overdriv]

dont count on it fitting inside the taco enclosure. best for it to live in its own enclosure, i might have something to put it in.

as far as cost, i dont expect to be paid -its sort of a science project for me. maybe ill have you cover shipping cost, we'll figure it out later im not concerned about $ on this.

Sounds good to me.

 

[mrb]

just a little update on the project, the microcontroller code is pretty much done, going to assemble the hardware probably tomorrow so we should see something working soon.

 

[overdriv]

just a little update on the project, the microcontroller code is pretty much done, going to assemble the hardware probably tomorrow so we should see something working soon.

Great Mrb, thanks a lot for your efforts.

 

[dipper]

mrb & overdriv,
This is my kind of project too.
i may have a project box for the pcb; let me know what minimum size you need and i can take a look and see what's in stock. no charge of course.

 

[overdriv]

Thanks Dipper for the offer. Since Mrb is building it I'll defer this to him.

 

[klhitman]

if that dont work for you let me know. i think i have some spare idec timers floating around the shop i might be able to send to you.

 

[kbeitz]

Can someone recommend a timing relay for 125VAC that will give me a one shot closure of the contacts for a couple of seconds and then open?

I want to put a counter on my Taco switching relay. I want to know how many times my system runs per day. I have the 125VAC counter but I don't want it to stay energized as long as the system runs. All it needs is a pulse.

http://www.grainger.com/Grainger/DAYTON-Time-Delay-Relay-6A855?Pid=search

 

[mrb]

ok, my counter is up and running on a solderless breadboard. now i just need to turn that into a circuit board for overdriv. few more days and you'll be counting. This thing turned out pretty cool ill post a pic tonight. 6 digits of red LED display....

 

[mrb]

its alive.... still tinkering a little bit with how it stores the count (count is in ram when operating) when it loses power (it does it now but i want to do it a little differently) i should get to hard wiring it on a circuit board this weekend.

 

[overdriv]

Wow! It looks like you have went to a lot of effort. It sounds like you enjoy this kind of project. Thanks!

 

[Travis E.]

That looks great MRB. Can't wait to see it on a board.

 

[overdriv]

Mrb, did you loose interest in the project? There is no hurry, just wondering the status of your work.

 

[mrb]

didnt lose interest. i have all the pieces sitting here including a housing, cable strain relief, etc. i havent had time to finish it yet hopefully that will happen this weekend.

 

[crackerjack222]

I just found this site and thread so I am late to the party, but I have built many "relay one-shot"s using a 24 vdc relay with a capacitor in series with the coil. Upon application of power the capacitor will conduct long enough for the coil to momentarily energize, then stay off for the duration of applied power and until power is applied again. I mostly used small relays with 1000 ohm coils and a 10 uf capacitor. I also put a resistor (about 47k ohms) to ground from the + side of the cap to make sure it discharged quick enough. If your applied power is ac then you would need a diode or rectifier bridge, if 120vac, than also a small transformer.

 

[mrb]

I just found this site and thread so I am late to the party, but I have built many "relay one-shot"s using a 24 vdc relay with a capacitor in series with the coil. Upon application of power the capacitor will conduct long enough for the coil to momentarily energize, then stay off for the duration of applied power and until power is applied again. I mostly used small relays with 1000 ohm coils and a 10 uf capacitor. I also put a resistor (about 47k ohms) to ground from the + side of the cap to make sure it discharged quick enough. If your applied power is ac then you would need a diode or rectifier bridge, if 120vac, than also a small transformer.

hmm good idea (but my digital counter with LED display and count stored in non-volatile memory is so much cooler )

 

[crackerjack222]

mrb, I agree yours is much cooler.
Now I know who to turn to when I have a real electronics question.

 

[overdriv]

Mrb, no pressure here, just hadn't heard from you in a while and was wondering. Heating season is over but this fall is just a summer away.
Thanks!

 

[mrb]

pm sent