help with electrical diagrams for ilford heads

[mitch brown]

hi
i need someone who can read the electrical diagrams for the two ilford 500 heads i have one is older and has a differen plug setup. i want to know if it would be possible to change the plug on tje older head and use it. i do have the wireing diagrams and it looks like the difference is the plug connects.
if anyone could look at the diagrams and tell me if it possible .
thanks
mitch

 

[George Nova Scotia]

Can you post the two diagrams or a link to them? If not I still might be able to help in the am since I have the all flat pin head and the newer diagram but the would mean tracing each wire... Based on the previous thread I doubt there is any difference but I guess you never know.

George

 

[mitch brown]

here are both diagrams .
thanks

 

[George Nova Scotia]

very interesting, on first glance they flipped the connector wiring. Let me take a second look and get back to you later today or Monday.

 

[Marco B]

here are both diagrams .
thanks

You've done a great job. It was about time someone uncovered these Ilford MG500 exposure system circuit diagrams for the units with the older 500C controller...

I asked Ilford Photo/ Harman directly, and they had nothing except the circuit diagrams for the units with the newer 500CPM controller.

Good job! And thanks for posting them here.

***
LAST THING: If you have scans of the circuit diagrams of the actual 500C controller too, please post them here in this thread!!!

You only posted the circuit diagrams of the older 500S power supply and the actual head as relevant for your question, but not the 500C controller.

Please post them for future reference and repairs, they are to hard to find!
***

 

[Marco B]

In addition:

Please post the component layouts of the 500S power supply and 500C controller too!

Thanks,

Marco

 

[Marco B]

Actually it seems you did post the older 500S power supplies component layout, as I now noticed there are some small changes compared to the documentation of the newer version I already had, although I still need to verify it with my unit, I have the slight feeling the component layout doesn't completely match the either one, but it is probably insignificant.

Than only the component layout and circuit diagram of the 500C controller are missing!

Post them if you have them.

 

[Marco B]

I now noticed the "round pin 2.jpg" file that Mitch attached in this thread, that shows the component layout of the 500S power supply, and that differs slightly from the documentation that I have for the power supply that comes with the 500CPM controller, according to the file name given by Mitch, also uses the 7 flat pin and 1 rounded pin connector.

Also, I have now dug up two photos of the inside of my older version 500S power supply, and it isn't consistent with Mitches posted component layout of the 500S power supply, and neither as I already knew, with the Ilford documentation for the 500CPM controlled units...

Just look at the position of the two large capacitors (the "beer cans", wrapped down with a plastic strip on the printed circuit boards), they are orientated at 90 degrees from what is visible in the both component layouts as described above (denoted as C1 and C2 in the component layouts).

This actually means there have been THREE different versions of the 500S power supply for the Ilford MG500 exposure system, two versions using the 7 flat pins and 1 "rounded pin" in the plug connecting the head, and one version like mine, using 8 flat pins...

The 8 flat pin versions are probably all controlled by the 500C controller, whereas the MG500 units with 7 flat pin and 1 rounded pin connectors for the heads are 500CPM controlled, but maybe also some units by the 500C controller.

Well, I hope I haven't lost to many people by now, my own head is spinning

So we still need the component layout for the "8 flat pin" variant of the 500S power supply, like mine, too... we do have the circuit diagram luckily now

Attached images below are from the inside of a 500C controlled 500S power supply with an 8 flat pin connector socket to connect to the enlargers head.

 

[George Nova Scotia]

Marco, I think the controllers may be interchangeable. I have a CPM controller (Ser # 5C50410) connected to a flat pin PS (SN 5S11507) and it seems to work fine. Sadly it's sitting on the bench as the heat absorbing glass is broken/missing in the head

 

[Marco B]

George, you may be right about the interchangeability of the controllers, if the connectors and plugs follow the same wiring schema.

Essentially, from the 8 wires going to the controller, 5 are doing no more than supplying the electronics in the controller with the appropriate voltages (ground, 0V, 5V DC, -5V DC, 12V DC and 12V AC) to make it work, and provide the switching voltages to control and switch the lamps by means of the functions and electronics provided in the power supply. The additional 3 wires direct the signals back to the power supply, 1 for each enlarger head lamp, and 1 to control the safe light and ventilator.

 

[Marco B]

very interesting, on first glance they flipped the connector wiring. Let me take a second look and get back to you later today or Monday.

George, you are right they significantly changed the wiring in the cable from the power supply to the enlarger head.

In the 7 flat pin, 1 round pin connector the connections are:
- Pin 1 is the ground
- Pin 2 30V AC
- Pin 3 seems unused...
- Pin 4 is connected to the 0V and switches the cooling fan in the head by means of relay RL2/1. Relay RL1/1 switches the safe light.
- Pins 5 & 6 120V DC enlarger head lamps
- Pin 7 & 8 should be 120V AC for fan

According to the notes written on the scans Mitch posted, and that seem to be OK after a quick verification:

In the 8 flat pin connector the connections are:
- Pin 1 120V AC for "Lamps common"
- Pin 2 120V AC for fan
- Pin 3 120V DC for the blue light in the head
- Pin 4 120V DC for the green light in the head
- Pin 5 0V or "Mains neutral" as written on the schema
- Pin 6 seems unused
- Pin 7 30V AC
- Pin 8 is the ground

Correct me if I am wrong George! (or anyone else seeing something wrong)

 

[ic-racer]

It looks like the pins on the new connector should connect to these wires on the old head:

1 to 8
6 to 3
5 to 4
7 to 2
4 to 5
8 to 1

 

[George Nova Scotia]

Marco & ic-racer: I'd agree to switch heads the connector would have to rewired. The 30VAC isn't connected in either head so 6,7 (all flat) or 2,3 (round in) are not needed, if fact I only see six wires in the cable (all flat) on mine. If you look at the two head diagrams the layout is the basically the same. The new head has an added interlock switch on the lamps. To switch heads you can cut and paste the pin numbers from one diagram to the other.

 

[ic-racer]

Matching the wires is the easy part. Finding a Jones/Cinch/Molex connector with a round #1 pin might be difficult. You might have to replace the connector on the power supply with a connector with all flat pins.

 

[Steve Smith]

It looks like the pins on the new connector should connect to these wires on the old head:

1 to 8
6 to 3
5 to 4
7 to 2
4 to 5
8 to 1

Is it possible that one diagram shows the connector from the front and the other from the rear? These figures show a complete reversal of the connections. Rewritten in numerical order, it is more obvious:

1 to 8
2 to 7
3 to 6
4 to 5

and therefore:

5 to 4
6 to 3
7 to 2
8 to 1



Steve.

 

[Marco B]

Is it possible that one diagram shows the connector from the front and the other from the rear?

The front/back issue you raise is a good one. Yes, it can get confusing. I do know the socket diagram of the socket for the controller shows the back / inside the power supply distribution of the wires, as I have checked the Voltages once when I had issues, so it seems likely the socket for the head is also displayed as the back, but I haven't checked that yet.

The socket layout for the controller is consistent and identical in both diagrams..., nothing changed.

 

[paul ewins]

I think this is the fourth thread on the Ilford 500H in the last week. I might be nice to have some sort of consolidated thread called "all you ever needed to know about the Ilford Multigrade 500 enlarger heads" just to make thing easier in the future.

BTW, I have a copy of the operating manual for the first version of the 500. It doesn't have schematics but does have exploded view drawings and parts lists for the head and power supply and part numbers for the rest. It lists adapter kits for nineteen different enlargers.

 

[ic-racer]

I know the Siemens connectors on my Durst have little numbers by each pin.

 

[mitch brown]

idon't have the diagram for the 500c controler. they where sent to me by someone else. i will ask if they have it. they where worried about posting the diagrams due to copywrite issues, i emaild simon at ilford for premission but haven't heard back yet but still posted it hope they don't mind. so are you guys saying just change the wire pin places and it should work?
thanks
mitch

 

[Marco B]

idon't have the diagram for the 500c controler. they where sent to me by someone else. i will ask if they have it. they where worried about posting the diagrams due to copywrite issues, i emaild simon at ilford for premission but haven't heard back yet but still posted it hope they don't mind.

Hi Mitch,

While I respect peoples worries about copyright issues, I also think this is getting a bit out of hand. We are talking about decades old equipment, that has gone out of production a long time ago. In addition, Ilford posted scanned documentation themselves freely available on their website.

Lastly, I contacted Ilford directly about this very same issue of the older type MG500 units circuit diagrams and component layouts through the response link on their website. They were friendly enough to answer that they didn't have it available, but would add it if they ever dug up anything from their archives.

Frankly, I think Ilford will, and should, not mind. Anything that helps old equipment - and our hobbies / work! - going, by allowing repairs, is beneficial to Ilford, not detrimental.

so are you guys saying just change the wire pin places and it should work?
thanks
mitch

Yes and No (oh isn't real life beautiful ). Yes if they need to be switched, no if you only need to replace the connector / plug but not change wire layout. This latter option was justly raised by Steve, with his question about the front/back layout of the plug, and whether or not Ilford mixed up the diagrams.

To determine if "No" is the case, I say "measure the voltages" on the plug in the power supply, so as to determine what is right and what is wrong... Get a multimeter.

Actually, since Ilford did change the plug by adding the pin, it still is likely they changed the wiring. Don't ask me why actually, since it seems no real significant change to the enlarger head was made requiring rewiring. The only reason I can think of than is that the changed layout allowed for easier wiring inside the 500S power supply and thus easier assembly / manufacture of the units. If you look at the photos of my unit that I posted, you can actually see that the wiring is quite complex inside, with thick bundled sets of individual wires. Maybe it was just a convenience / manufacture issue?

But maybe someone else with more electronics knowledge can give a more informed comment about the re-wiring.

 

[mitch brown]

ok what i understand is that if the head i am useing ( w/ round pin ) go"s bad i can take the plug off it and use it on the other head ( all flat pins ) by changing where the wires go on the plug.
As someone said earler is ther a way that the 2 threads can be made avalible and easy to find for others when they have problems. mybe combind them.

thanks
mitch