Search results

Search Forums New Posts
  1. bertus

    PWM that will work with a reversible power supply

    Hello, In the given circuit IC1b, IC1c and IC1d will perform the PWM action. It is controlled by the voltage coming from IC1a. Bertus
  2. bertus

    What component is this?

    Hello, The capactors are indeed 3.3 μF. The voltage will not be that high, as on the left I see a 32kHz watch crystal and on the right a crystal oscillator. Bertus
  3. bertus

    Comedy Thread

    Found at AAC:
  4. bertus

    PWM that will work with a reversible power supply

    Hello, Could you use a DC control voltage? Then have a look at the attached article. The control voltage can be in place of the potmeter. At ca. 52 % Vcc the speed is max forward. At ca. 33 % Vcc the speed is 0. At ca. 5 % of Vcc the speed is max reverse. Bertus
  5. bertus

    Capacitor Rating

    Hello, Perhaps the manual does not fit the monitor you have. What is the type number of the monitor? bertus
  6. bertus

    Stage Line 500W amp repair project

    Hello, If you want to have a good read-up as @WHONOES said on opamps, have a look at the PDF I posted in post #545. ( https://www.mouser.com/pdfDocs/analogengineer%E2%80%99scircuitcookbookopamps.pdf ) An other PDF will be "opamps for everyone"...
  7. bertus

    Pulsed signal

    Hello, Please turn of the auto translate in your browser. What are you trying to hide with all those black stripes in the posted images? We still have no idea what you are upto. Bertus
  8. bertus

    I’m looking for an elegant solution to power an old radio with 220v dc

    Hello, It depends on the type of tubes/valves. There are tubes/valves that have the same current, but different voltages. There are tubes/valves that have the same voltage, but different currents. Just look in the datasheets of the tubes/valves for the type used. There are a couple of...
  9. bertus

    Wire connection point to point?

    Hello, It is likely tinned copper wire: https://www.newark.com/w/c/cable-wire-cable-assemblies/tinned-copper-wire?ost=wire Bertus
  10. bertus

    COVID-19

    Hello, We have reached 100 million cases over the past year: https://www.worldometers.info/coronavirus/ It seems that the USA is good for 1/4 cases and india for 1/10 cases. Bertus
  11. bertus

    I’m looking for an elegant solution to power an old radio with 220v dc

    Hello, Wich version do you have? Here is a manual for the E,M and P version: http://www.shortwaveradio.ch/lib/exe/fetch.php?media=manuals:to_08-10-119.pdf You will still need an 28 Volts for the heaters of the tubes. Bertus
  12. bertus

    I’m looking for an elegant solution to power an old radio with 220v dc

    Hello, When you use a 220 V to 120 V in reverse, the output voltage will be 220 V AC, when rectified the voltage will be about 310 Volts DC. Bertus
  13. bertus

    Automatic links

    Hello, @Harald Kapp , In the old version, the link is not shown. The link only comes up in the new layout. Bertus
  14. bertus

    Stage Line 500W amp repair project

    Hello, You can change the size of the electrolytic capacitor by using the right mouse button. A menu will pop-up like this: You can also change the board style with the two bars in the menu: Bertus
  15. bertus

    Stage Line 500W amp repair project

    Hello, You have to unzip the file. You will find the following files in the unzipped directory: The software uses a browser as user interface. Bertus
  16. bertus

    COVID-19

    Smart distancing system:
  17. bertus

    Stage Line 500W amp repair project

    Hello, If you do not want to use paper, you could use a piece of free software called PEBBLE. It has all kinds of components and boards to "draw" your PCB. https://picaxe.com/software/third-party/pebble/ Bertus
  18. bertus

    And now something weird

    Weird? Maybe "cool"?
  19. bertus

    Stage Line 500W amp repair project

    Hello, The opamps are this way connected in the housing: Bertus
  20. bertus

    Heathkit amp,model EA-2

    Hello, 1 MegOhm will be to high for a wirewound potmeter. Here is the schematic from jabse : ea-2.pdf Bertus
Top