240 to 115 volt supply is common. Just has to be big enough, and not to big. Connections can be moved over. Available on rs-online from 25VA to 5kVA
Big Wehman, Toyo 5x7" and a small Chamonix
240 to 115 volt supply is common. Just has to be big enough, and not to big. Connections can be moved over. Available on rs-online from 25VA to 5kVA
Big Wehman, Toyo 5x7" and a small Chamonix
It is mostly used for RA4 process.Originally Posted by Oslolens
Could you please share the setup you have? What is the timer and power supply that you are using?
sorry for double posting. It seemed the messages didn't post and then they did. And what is the power supply and the timer that you are using? Just curious, also I don't want to reinvent the wheel.
also I guess it is a good idea to check the sockets:
https://www.largeformatphotography.info/forum/showthread.php?137740-Ilford-500-Bulb-Blowing-Blues&p=1380920&viewfull=1#post1380920
This is a different head, but I guess it still makes sense.Sockets?
One of my D5500's was blowing bulbs. Oxidation in the lamp socket produced an intermittent low voltage. That power supply has a PWM stabilization circuit. I suspect some low voltage at the socket caused the thyristors to open all the way. Since the thyristors are right on the mains, the 81V lamp could get a jolt of 120V.
240 to 115 volt supply is common. Just has to be big enough, and not to big. Connections can be moved over. Available on rs-online from 25VA to 50kVA.
Sorry, mine is B&W: cold head with two small 230 to 115 trafo, on for the lamp and one for the heater. Timer is normal.
For RA4 process, you could use high quality LED, but sufficient watts, the high output LED need cooling, but maybe not a fan. Several amateurs have done this for b&w, but if they do color heads, I think they use red, green and blue LEDs. Do a search online, you might end up there anyway.
Big Wehman, Toyo 5x7" and a small Chamonix
Thanks!
I will have an update when the new bulbs arrive next week.
Drew gives good advice to get this running if the power supply can't be repaired.
DO NOT omit the coollng fan under any circumstances!! That would be a great way to prematurely age the filters and certain other things too. Although these filters don't fade per se, overheating them will lead to the coatings progressively spalling off. Spectral sensitivity also shifts when dichroic filters overheat and will affect color repeatability. In terms of rewiring the circuits independently and bypassing the power supply, you can use most of the original wiring in the head itself, but need to trace which apply to the 115 circuit simply by tracing them with a continuity tester from the appropriate plug and labeling the end of the respective lines with colored electrical tape. You might have to omit certain minor amenities like the tiny lamps which optionally light up the colorhead dials (I don't like them on anyway). Do you have motorized focus and height on your unit? If so, you'll also need to see which voltage that runs on. Hopefully, you won't need to rewire. But another option would be a generic dual-voltage power supply. These are common but need to be consistent within plus or minus about 5 volts, just as your outlets should.
Agree, except if you have 5x3W of LED with most of the heat going up, instead of 100s of W going through filters.
Big Wehman, Toyo 5x7" and a small Chamonix
So we could only try the setup today.
We put two ELH lamps. We connected the timer but it wasn't turned on. The fan was connected directly to the mains and it was working.
When we turned on the EST 301 both lights turned on. And after 20 secs the light on left blew, and shortly after the right one.
When we measured the voltage on the socket it read 150 volts.
I guess we will try to find the problem by checking the EST 301 first, and then the wires and the socket.
What could be faulty besides the power supply and the wires?
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