8mm Forum: Specto 500 8/16 120V 300W halogen conversion

This is topic Specto 500 8/16 120V 300W halogen conversion in forum 16mm Forum at 8mm Forum.

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Posted by James Gillespie (Member # 4030) on November 22, 2013, 09:23 AM:

I am hoping to learn from members who have experience with halogen conversion of the Specto 500 lamphouse. Would like to draw 120V power, for the QLV-1 halogen lampholder, from the availble 240V source if possible. If necessary, I am prepared to run a new 120V line to the projector specifically for the lamphouse and possibly an extra cooling fan.
Cheers, James

Posted by Maurice Leakey (Member # 916) on November 22, 2013, 09:59 AM:

You mention you have a 240 volt source. Here is what my Specto 500 has been converted for using.
http://www.uklightbulbs.co.uk/cgi-bin/site-editor.pl/8/-ecommerce?action=item;item=A1247;eid=P405716

Posted by Michael Wright (Member # 1387) on November 23, 2013, 02:44 AM:

Hi Maurice, would this lamp be suitable for the older Spectos that originally had a 30 volt lamp? Cheers MIKE

Posted by Maurice Leakey (Member # 916) on November 23, 2013, 03:51 AM:

No, Michael.
The 30volt lamp was 100watt, the model 500 had a 115volt 500watt lamp. Therefore, the 100watt model would have insufficient cooling.

Posted by James Gillespie (Member # 4030) on November 27, 2013, 10:36 AM:

... I am midway through a conversion to 120v 300w Halogen ELH lamp!
... Cleared away old resistor/pre-heat coil from old lamphouse.
... Ran new 120v supply to projector, fuse, switch, etc.
... Today will shop for a quiet computer cooling fan to add in the lamphouse.
... Cheers, James

Posted by James Gillespie (Member # 4030) on December 06, 2013, 11:57 AM:

Dino had mentioned that on his Specto there was a transformer reducing the lamphouse current to 110Vac.

With my Specto the 120V 500W lamp part of the circuit was dependent on the
Resistance in the pre-heat coil, and even varied with change in motor speed.
So, cleared away the old coil and left motor circuit intact at 240V.

So I have run a separate 120V line to the projector for the halogen lamp and additional CPU cooling fans run off of a wee 12V 1Amp transformer.

I removed all obstructions and established required 'working distance' of lamp to film plane, and have amazingly brilliant light in the frame but a strange large circle of fainter light from the reflector bulb ... Will post pics later

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