Yashica P8 knowledge?

[Richard Cunningham]

Richard, don't do anything dangerous. If you don't feel comfortable with electricity, consider asking someone who has some basic knowledge to assist you. Remember that tour projector has been manufactured at a time where safety standards were not as high as they are now and, of course, with time some parts may go wrong and become less safe.

Thank you for the warning and for your concern, Dominique. I'm comfortable working with electricity, and of course the projector will be unplugged and I'll ground it even after unplugging it to ensure nothing is left in any components to give me a jolt.

Richard

[Richard Cunningham]

I thank Dominique for his very clear instructions following my earlier comment.

It is true that a declared voltage may not necessarily come out of your mains sockets. Here in the UK our declared voltage is 230, however the supply companies are allowed a tolerance of -6% up to +10%. This actually means that what comes out of our sockets could vary between 216.2 volts and 253 volts. Quite a difference !

As Dominique says, checking the supply voltage with a meter will show what you are actually receiving.

Maurice

Thanks, Maurice. I'll be sure to check the input voltage, too. I have a good multimeter that is up to the task.

Richard

[Richard Cunningham]

If at the slowest setting it is only just too fast it may be set for 50hz instead of 60hz. If it has and AC motor this could cause it to run 20% fast. I don't know the model so I don't know the type of motor fitted.

Thanks Brian. I'll look for a model # and post it here if I can find it, but is there likely to be anything I can do to adjust the motor up to 60hz if I can determine that it's set at 50?

Richard

[Richard Cunningham]

Richard, don't do anything dangerous. If you don't feel comfortable with electricity, consider asking someone who has some basic knowledge to assist you. Remember that tour projector has been manufactured at a time where safety standards were not as high as they are now and, of course, with time some parts may go wrong and become less safe.

Thank you for your concern and your warning, Dominique. I'm comfortable enough working with electricity, so I don't mind trying to do a few simple tests.

Richard

[Richard Cunningham]

Sorry for my confusion. I didn't realize a second page had been started, and I thought my previous replies had failed to post. So I reconstructed from memory what I'd written before, but discovered my error after posting only the second version to Dominique.

Richard

[Richard Cunningham]

I thought I had a reliable multimeter--and maybe I do--but I'm getting a voltage reading from the wall socket of 156 volts. When I checked another socket that's what I got there, too. I find this hard to believe, so I suspect my multimeter might not be as reliable as I'd thought. I'll check with a neighbour to see if he has one. If not, I'm not sure. I may have to buy a new one, if I can't come up with a way to test the one I have.

I also opened the two access panels on the projector. One's on the bottom, and the other on the side. The one on the side exposes only mechanical elements: the drive belt, pulley, and gears. The panel on the bottom gives me access to the wiring, the rheostat that controls the amount of current to regulate the speed, and the backside of the 2 toggle switches: the one that lets power through from the cord, and the one that activates the lamp. There's a part number on the rheostat, but I didn't see one anywhere else. There was one other component: a capacitor, maybe? But the was it. Nothing anywhere that indicated any kind of adjustment is possible.

The motor is has its own compartment at the back of the projector, and I wasn't able to loosen the screws that hold it in place. I had thought that maybe there'd be a tag of some kind on the motor itself declaring its ranges and limitations.

I'm now inclined to be suspicious about the power supply. At least until I get that confirmed, one way or the other, I think that looks like the more likely cause of my problem, based on what I've learned here.

Thanks, everyone.

Richard

[Richard Cunningham]

I was able to borrow a meter from my neighbour, and it reads the voltage as a much more credible 122 volts. So once again, I'm not sure where the problem might be.

Richard

[Maurice Leakey]

Richard
I suggest that the problem might be the speed adjusting device.
No doubt this is a wire-wound rotary resistance. Rotation of the knob varies the resistance, hence the motor's speed from slow to fast.
It could be that some turns have shorted out, but why this should happen I really don't know.


Maurice

[Dominique De Bast]

Any progress, Richard ?

[Richard Cunningham]

Richard
I suggest that the problem might be the speed adjusting device.
No doubt this is a wire-wound rotary resistance. Rotation of the knob varies the resistance, hence the motor's speed from slow to fast.
It could be that some turns have shorted out, but why this should happen I really don't know.


Maurice

I've been thinking the same thing. Maurice. I really can't imagine a more likely explanation. I guess I'll see what I can find online in the way of replacement parts. Time was, I could go to Radio Shack and get such a part fairly easily. But all our Radio Shacks faded away decades ago. I was in Tokyo a few years back, and they have bins and bins of parts all along a relatively well known street to which a friend took me. Not that that's what we were looking for; there was a lot of other stuff there, too. But always having been a bit of a tinkerer, the electronic parts caught my attention. Does me no good now, though. But maybe the part number on the rheostat will enable me to buy a replacement. This won't happen soon, though.

Thanks for your continuing help,
Richard.

[Richard Cunningham]

Any progress, Richard ?

Hi Dominique.

I wish I could say so, but I'm afraid not. I think Maurice is right, that the rheostat is malfunctioning, but until my new multimeter arrives (supposedly next Friday) I can't even attempt to test this hypothesis. Nor am I inclined to take any such test at face value. The most convincing test would be to replace the part, which, as I suggested in my reply to Maurice, might or might not be possible.

Thanks for your continuing interest.

Richard