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  1. (*steve*)

    New project - 1967 oscilloscope restoration

    Sorry, I don't get you?
  2. (*steve*)

    New project - 1967 oscilloscope restoration

    The electrolytic capacitors all read well over their marked value, that's a pretty good indication they're leaky. If anyone can confirm whether that dual 0.2uF 1500V cap is likely to be electrolytic I'd be very appreciative.
  3. (*steve*)

    New project - 1967 oscilloscope restoration

    I picked up this from a for sale group (these were the photos on the site) I was immediately attracted to the cut off twin flex! :) The guy who sold it to me told me it has been sitting in a shelf for years since his sister bought it from a school sale. So no real idea of the history of...
  4. (*steve*)

    Voltage regulator voltage too high

    If they were really cheap, you might not have what you think you have. I found some cheap lm337's that were not lm337's :-(
  5. (*steve*)

    EG&G 5210 Lock in Amplifier

    There are regulators in the both of the shielded boxes in the 5210 -- have those been checked too? Although I'm not sure they'd make the device lock up. Presumably "lock up" means the buttons don't do anything? Correct?
  6. (*steve*)

    EG&G 5210 Lock in Amplifier

    And the user manual (including schematics) for an earlier version (5104) Too big to attach... here
  7. (*steve*)

    EG&G 5210 Lock in Amplifier

    And some high level information about this model
  8. (*steve*)

    EG&G 5210 Lock in Amplifier

    Here is the user manual. (just for reference)
  9. (*steve*)

    EG&G 5210 Lock in Amplifier

    @cchu2k asked the following questions via PM, and I have finally done as promised and placed them in a thread. I've taken a month and a half to do this... sorry.
  10. (*steve*)

    filtering a 3000V power supply output.

    Here's the 1000V test using the electrophoresis power supply. The whole setup (note the special high voltage cabling!) And closeup of the caps I'm still seeing a lot of ripple... That's 500mV per division, but with a 10x probe, so anything up to 20V of ripple. Hmmmm...
  11. (*steve*)

    filtering a 3000V power supply output.

    I've just connected up the 450V caps in parallel with these TVRs, and they seem to work well. Using 450V 270uF caps, all the in series charge up within about 10V of each other with the power supply delivering around 1080V. Disconnecting the power supply and discharging one cap, then...
  12. (*steve*)

    filtering a 3000V power supply output.

    The tvs works like a zener diode, I've just run some tests using my 1000V regulated power supply. I'm testing a 1.5KE400A, and on my multimeter they don't show any leakage up to about 395V, where it rapidly increases to 1mA at 407V. Something that is really interesting is that they clearly...
  13. (*steve*)

    filtering a 3000V power supply output.

    The tvs diodes do not seem to have as sharp a knee as a regular zener diode. So I'm not sure exactly how much current will flow. I might do some tests on some 400V tvs diodes I do have on hand. The datasheets are a little hard to interpret. The idea of this circuit is not to balance the...
  14. (*steve*)

    filtering a 3000V power supply output.

    I currently have a power supply capable of 250W output, with the output voltage adjustable from 5V to 1000V (yep, that would be 250mA at 1000V). I'm soon to get a similar power supply capable of 600W and 3000V. These are deadly (I know that). They are electrophoresis power supplies, and I...
  15. (*steve*)

    Tektronix TDS3054 data acquisition failure

    Unfortunately not :-(
  16. (*steve*)

    I need a electronic circuts for 2 v dc to 5 volt3 ampere out put

    You need to find a dc-dc boost converter capable of more than 6A. 7.5 to 10A would be best. Note that you'll need to ensure it starts at 2.5V -- some may not. If you went to design one, start by looking for a chip that satisfies these requirements (possibly using an external switching...
  17. (*steve*)

    I need a electronic circuts for 2 v dc to 5 volt3 ampere out put

    What is the input voltage? Are there any other requirements? What are you using it for?
  18. (*steve*)

    TO-220 to SMD

    I think you're describing a TO-263 or D2PAK. Whilst you may be able to butcher a TO-220 into something like that, maybe you can find a suitable replacement in the correct package.
  19. (*steve*)

    Power Issue?

    Yeah, and I totally ignored possible problems with the unregulated DC rail. I'm glad you found it.
  20. (*steve*)

    Power Issue?

    4.7v from a 5v regulator is not good. Is it hot? If so there is most likely some sort of overload. Is the voltage stable, and the regulator cool? It may be a fault regulator. Does the voltage vary, from a max of 5v down to something a lot lower? (You may need an oscilloscope to check...
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