Search results

Search Forums New Posts
  1. bertus

    Sensistor vs Thermistor

    Hello, You are heading in the right direction. This is what the wiki has to tell about the sensistor: https://en.wikipedia.org/wiki/Sensistor Bertus
  2. bertus

    Comedy Thread

    The Complete Edition of Murphy's Laws
  3. bertus

    My Li-Ion Battery Charger Circuit Is Not Working As Expected

    Hello, Read this article on the battery university about charging li-ion batteries: https://batteryuniversity.com/learn/article/charging_lithium_ion_batteries Bertis
  4. bertus

    Why is it so hard to find ceramic capacitor kits that have a 3.3pF in it?

    Hello, You can even gimmick a low value capacitor with a piece of twisted wire. Read this article about it: http://sm0vpo.altervista.org/begin/gimmik-0.htm Bertus
  5. bertus

    For Sale: Heathkit ET-3100 & ET-3200 experimenters

    Hello, I found the units on internet, from some collectors: http://www.heathkit.nu/heathkit_nu_ET-3100.html https://www.system-cfg.com/detailcollection.php?ident=160 Bertus
  6. bertus

    Part Replacement in Circuit

    Hello, That is half a theremin. It only controls the pitch and not the volume. A real theremin controls both. A theremin is not a real beginners subject. It contains several oscilators that must be adjusted for good results. This page has links to several theremin schematics...
  7. bertus

    HELP!!! I have a fault -- Read me FIRST

    Hello, You also might find a lot of tips in this resource: Troubleshooting and Repair info pages It will also help to have a (service) manual at hand. This resource has some links to sites that can provide manuals: Service manuals and schematics Often are faulty caps a problem in devices...
  8. bertus

    PCB for Dishwasher repair

    Hello, Stay safe when poking around a mains powered board. Read the following page for safety guide lines: http://www.repairfaq.org/sam/safety.htm Bertus
  9. bertus

    LM386 Amplifier Module help

    Hello, @PETERDECO , Then I still don't get your schematic. The LM358 is a low power dual opamp: Pin 6 would be the input of the second opamp. Bertus
  10. bertus

    LM386 Amplifier Module help

    Hello, The LM386 can not work when pin 1 is grounded. You are basicaly disabeling half of the differential amplifier: Bertus
  11. bertus

    LM386 Amplifier Module help

    Hello, @PETERDECO , I also am missing the zobel network on output: The capacitor and resistor are there for stability and to avoid oscillations. Bertus
  12. bertus

    LM386 Amplifier Module help

    Hello, I assume the key fob is working on a button cell of 3 Volts. Wich LM386 module are you using? What is the supply voltage of the LM386 module? It needs at least 5 Volts to work. The max voltage for the LM386 is 12 Volts. Bertus
  13. bertus

    How can a MOSFET in TO220 handle this much current?

    Hello, Here I found an other reason for the limited current of the TO 220 mosfets. The bondingwires between the chip and the legs are very thin and will burn when to much current is going through them. On the digikey page on cooling you will find an image of the internals of a TO 220 (figure...
  14. bertus

    Weird Voltage divider issue

    Hello, When using a breadbord, you can have bad contacts that are intermittend when a part is moved. The contacts in the breadboards are strips that can go bad when a to thick wire has been forced into it. Read the attached PDF and have a look at the image I post. Some breadboards have a break...
  15. bertus

    BBC Micro:Bit?

    Hello, There seems to be a website for the micro:bit https://www.microbit.org/ There even seem to be suppliers all over the world for the micro:bit https://www.microbit.org/buy/ Bertus
  16. bertus

    How can a MOSFET in TO220 handle this much current?

    Hello, Did you read this on page 2: Note 6 : Package limitation current is 75A. Bertus
  17. bertus

    LM1117 linear regulator.

    Hello, A linear regulator will make some heat thet must be dissipated. A TO220 version has the advantage that a heatsink can be mounted. A switching regulator will make some noise, but be much more efficient. Recom makes a switching version of the 7805...
  18. bertus

    Old timer trying to regain memory

    Hello, Welcome to this forum. We are open for all questions and will try to find solutions. Look at my signature. Bertus
  19. bertus

    LM1117 linear regulator.

    Hello, As the TO252 is much smaller as the TO220, the cooling will be less. In the datasheet a temperature rise per watt of 45 C/W is given: Here is also a comparisson between the package sizes: https://e2e.ti.com/blogs_/b/powerhouse/archive/2015/08/27/overview-of-voltage-regulator-packaging...
  20. bertus

    Recommendation for side cutters

    Hello, There are some wiha side cutters on amazon...
Top