Suggestions, please!!!

This may have something to do with why you can't re-strike immediately, although probably has nothing to do with why the bulb is going in the first place.

I don't know anything about Vic-5's, so that's all i can offer!

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Problem: Xenon shut down during operation...

What was the fix? I have to look up the resistor and capacitor numbers again, but several RF Suppression Caps in the lamphouse were fried. These caps also tied another circuit to ground via a bus.

Also, in the power supply, there were a few bad diodes w/bad connections!

I've found a faulty switch that perhaps has caused all the stops.
However I had just today the same difficult starting the xenon after 2 min. stop.

Since our rectifier never had these problems we think that there should be a problem.

Also, We've noticed the following:

1. The amperometer is not fixed, it is "shaking" about 2/4 amps.
2. The lamp has 1 month and is too black. The last one became too black in the same manner.

We are going to change the diodes, then we will check the current with an oscilloscope to see where is the problem.

If you have other ideas... The rectifiers is made by IREM

Bye!

Re; the lamp stopping after it has struck, perhaps a micro-switch in the STOP timer may be loose in its mounting or faulty. Have had this a few times. The lamp cannot strike, even with the lamp switch on manual until the switch makes contact again.

With our first sets of Cinemeccanica consoles many years ago, we had difficulty in striking bulbs. We beleive this was due to the points in the spark gap being exactly that - POINTS!. The corona effect allowed the charge to leak off to early. Whether that was the case or not, ignition was dramatically improved by removing the centre electrode, and filing the end electrodes to a rounded point (an aperture file works well for this). The points were set to about the thickness of a dime apart.

Good luck!

I'm going to buy a new set of diodes.
Can I buy them in electric shops (industrial electric shops) os should I have to order them directly to IREM?

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IREM told me that my rectifier requires 72 HAR 40.
Seems that my rectifier has 72 HFR 100. What is the difference?

Thanks for the tips, will be precious!

The first digit is the current
The second digit is the lead
The next two letters indicate series
The third letter (if any) is the "R" for reverse
The last numbers is the Peak Inverse voltage (x10).

Thus, a 72HFR100 would be a 70amp diode with a red covered attached lead, a reverse diode (red), and has a PIV of 1000 volts.

A 70HFR100 is the same thing without the lead.
A 71HFR100 is the same thing but with a bare attached lead.

IREM tends to use "HAR" series which has a different breakdown. The "A" stands for "avalanche."

IREM tends to "design" their stuff such that the components are running just about at spec with no headroom. This is true of the diodes, contactors and wires.

For 3KW and below rectifiers, 85 amp diodes will do. There is no point in keeping all the various sizes. I generally recommend a high PIV...800 - 1600...depending on what is available (it is amazing how that fluctuates with some suppliers). Nowadays, I don't seem to be having any trouble getting over 1000PIV. The higher PIV will protect them against spikes, to some degree.

As to the leads, they are harder to find and cost more. I have made up leads that I attached with screws/nuts to standard diodes for those rectifiers that so need them. I don't like the preattached leads since some rectifiers (ie the LP associates and it's MANY copies) tend to need about 1/2" more lead than the preattached ones give you. Therefore, the leads are under stress. Whereas we make our leads, they are crimped and soldered, never had one fail.

Steve

Thanks for all the info!

We have a 110A rectifier with a 3k lamp.

If I've correctly undertood your instrucions better diodes would be

82HAR100, right?

P.S. A bit OT: "lamp doesn't strike" or "lamp don't strike"?

Bye
Antonio

"Lamp don't strike" would be "Lamp do not strike," which is incorrect, since "lamp" is singular, and "do" is the plural form. Either that, or it's an imperative, meaning, "Lamp! Do not strike!"; few people go around ordering their lamps like that, though ;-)

--jhawk