| Author | Message | ||
     Just_ziptab |
I need an 120 volt inline relay timer to fire a magnetic solenoid several times for a couple of seconds when it receives an input signal and then locks in until the input signal goes away.100% duty cycle. What I have is an air door on my wood burning boiler that sticks closed from tar buildup or ice. The solenoid fires when there is demand and pops the door open. When the door sticks,the solenoid overheats because the core is not fully pulled in and it melts the shellac on the coil windings...changing the resistance and blowing the 3 amp fuse.Of course, when the fuse blows, it's too late and the solenoid is ruined.If it could fire a few times before it locks in,it would surely break loose the stuck door. Anyone? This is the solenoid: http://www.grainger.com/product/DORMEYER-Solenoid- 4X240 | ||
| Natexlh1000 |
It's too bad it's an AC solenoid. If it was 12V or something, you could adapt automotive starter solenoid. It would probably rip the door off the hinges  You think you could adapt a gear motor with a linkage instead? those are capable of massive torque. Like a windshield washer motor with a "turn off" contact that stops it when the door is done opening. Picture this: http://www.allelectronics.com/make-a-store/item/DCM-565/12-VDC-AUTO-WINDOW-LIFT-MOTOR-LEFT-HAND/1.html hooked up so that if left running, the air door opens and closes over and over again. Set it up to run in series with contacts that open when the door is open. A second set of contacts would stop the motor when it gets to the closed position. You could cause the original solenoid drive circuit to click a relay instead to trigger the opening contacts.  | ||
| Reepicheep |
I built something like it that was triggered off temperature for a fireplace fan. It would be straightforward to convert it to simply do a series of whacks and then hold on. Heck, it could even sense the temperature of the solenoid coil and work that way. So it's really just a general purpose thermal cutout device. What is driving the current relay? Is it DC controlling the relay coil? Like 12V? | ||
| Hootowl |
Suggest you rig a switch that closes when the door opens so the system knows when to stop pulsing the solenoid. | ||
| Just_ziptab |
A 120V digital Love temperature controller runs the air door.Opens the door at 174°F and closes it when the water temperature hits 185°F.It supplies 120V current to the air door solenoid. A gear drive servo would be ideal,but it's a very harsh environment in that air door area.Industrial grade would be expensive too. I'm looking for some sort of device that I can simply wire inline in the main control panel...like a 120volt flasher relay and a 120V delay timer relay.I see many types on eBay for cheap,but I have no idea how they all work or what parameters can be tired together between the two.  | ||
| Kenm123t |
Guys its called a actuator motor Zip do you have picture of what your trying to control? A actuator is rated in inch and or ft pds Jams will be a thing of the past We do this all the time power close spring open for a air damper would work best. PM me and Ill give you my # | ||
| Teeps |
Bad Web members! Is there anything we can't fix? | ||
| Just_ziptab |
I don't want to reinvent the thing mechanically.....there has to be an inexpensive way to make the solenoid cycle several times before it locks in. I have it set to give the linkage a running start before the slack is taken up.... to help pop the air door open when it does stick. That seems to have helped,but not a "cure all".  Technical Specs on the solenoid: Type Laminated Stroke Range1/8 to 1" Pull Force Range64 to 128 oz. Width (In.)1-13/16 Depth (In.)2-1/16 Length (In.)2-1/2 Coil Volts120VAC Seated Amps0.43 Seated Watts17.9 Coil Resistance (Ohms)20.5 Terminalsolder Lug Coil Amps @ Max. Stroke4.90 Mounting Holes2 x 1-3/8" Gravity Value (Oz.)4.32 | ||
| Kenm123t |
Actuators are easy cheap way out is to use dual solenoids side by side with sloppy linkage another way is a spring in the linkage let the coil seal and the spring will pull the damper open | ||
| Just_ziptab |
I like the dual solenoid idea! ! A electrical friend from my old work place came up with a hand held,stand alone PLC that can easily be programed to fire the solenoid as many times as I want before it locks in. Uses an ice cube relay as a damper/buffer to the system.Run a wire thru the conduit that already goes to the boiler and mount it inside the basement wall...  | ||
| Kenm123t |
damper motors are $ 100 plus \ I ll look and see if I have any thing in the used bin you can have . You may have to use a 24v secondary transformer of about 40va | ||
| Just_ziptab |
Thank you Kenm123t for your thoughts,time and willingness to help! "Buellers in force". I think I will go with the hand held controller my friend has for cheap. All I need is an ice cube relay and base.  |
