There must be someone out there who can tell me what the filament voltage normally is on projection tv tubes.
I'd imagine it really varies from set to set as it does with normal tvs.
The one I'm interested in knowing is what the filament voltage is of a Zenith that uses the 170ACB22 type CRT. If anyone happens to know this tube.
Thanks.
I'd imagine it really varies from set to set as it does with normal tvs.
The one I'm interested in knowing is what the filament voltage is of a Zenith that uses the 170ACB22 type CRT. If anyone happens to know this tube.
Thanks.
Well, I know that it has to be less than 30,000 volts. When you hit that point, that is when radiation starts to be emitted. I work in the medical field repairing medical equipment. Most of the older vital signs monitors use CRTs and when we fix them, we have to assure everything is safe. We have KV meters to measure the higher voltages. One nice thing, I have a great source for parts, they are always trashing old equipment.
That's the anode voltage for accelerating electrons to the tube face.
I'm interested in filament, the voltage which is usually 6.3V for very old tubes and equipment but in tv now seems to vary from set to set.
Interesting idea about the 30kv thing though. The HV in most projection sets is actually 30KV but can be slightly higher for very large ones. The emission occurs even below 10KV, but is shielded more at higher voltages.
In the projectors, the tubes have lead plating lining the area immediately behind the face and then protective shielding in front of the face.
I do realize that this is a very dangerous type of equipment to be working on though, so my intention is certainly not to give anyone ideas about opening up a projection tv, or any tv for that matter unless they are professionally knowledged in procedures necessary to deal with such equipment.
I'm interested in filament, the voltage which is usually 6.3V for very old tubes and equipment but in tv now seems to vary from set to set.
Interesting idea about the 30kv thing though. The HV in most projection sets is actually 30KV but can be slightly higher for very large ones. The emission occurs even below 10KV, but is shielded more at higher voltages.
In the projectors, the tubes have lead plating lining the area immediately behind the face and then protective shielding in front of the face.
I do realize that this is a very dangerous type of equipment to be working on though, so my intention is certainly not to give anyone ideas about opening up a projection tv, or any tv for that matter unless they are professionally knowledged in procedures necessary to deal with such equipment.
Not to cause flaming but, CRT voltages can easily reach 100,000 volts on the larger scales.
example: original Apple Imac had 15,000 volts in a 15" CRT
Sony Trinitron 15" monitors are around 25,000 volts.
always excercise excessive caution while working on CRTS!
example: original Apple Imac had 15,000 volts in a 15" CRT
Sony Trinitron 15" monitors are around 25,000 volts.
always excercise excessive caution while working on CRTS!
i basically meant to state that but got away from the point too soon.
Yes, the voltages just under 30kv are normally seen in most consumer products like computer monitors and rear projection sets. But in larger or brighter applications, there are simple reasons why much higher anode voltages would be required.
Yes, the voltages just under 30kv are normally seen in most consumer products like computer monitors and rear projection sets. But in larger or brighter applications, there are simple reasons why much higher anode voltages would be required.
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