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  1. fixit7

    Runtime of clock using alkaline D cells instead of AA batteries

    I have a wall clock that uses 2 AA batteries. I would like to use a transformer, but I get frequent power outages. The clock uses about 30 mAh. It lasts about 2 months before it starts losing time. (Around 2.0 volts for the 2 batteries.) If I go with 2 D cell batteries, what kind of run time...
  2. fixit7

    Forward voltage of blue 3 mm led

    I have this package of 30 3 mm blue leds. I do not recall where I bought them. The pic shows one of them powered by a 18650 battery. I was wondering what the forward voltage is?
  3. fixit7

    [SOLVED] 12 vdc led running very hot

    I bought some 12 VDC 5 mm red leds. They work find but... when I touch the wires going into the led, they were hot enough that I had to remove my hand. That does not seem normal.
  4. fixit7

    Rebuild low end computer speakers

    I bought some Inland Pro Sound 2000 speakers from a thrift store. It is an amplified system putting out about 7 watts. They sound pretty poor. I remember making my own 8 ohm speakers years ago using a woofer, midrange, tweeter, and a cross-over network. Can I do that also with this system...
  5. fixit7


    I am trying to sell this. It was salvaged from a Yamaha receiver. I was told it was a shielded power transformer. If it is not, I would appreciate knowing what it is. https://www.ebay.com/itm/Bando-Shielded-Power-Transformer-Yamaha-BD21A35E-0004/202744916702 It weighs in at around 9 pounds...
  6. fixit7

    Minimize effect of IR bulbs on image

    The IR bulbs are great for nighttime surveillance but not really needed when there is ample light. As you can see, in this image the IR light is reflecting off the blinds. https://imgur.com/uQZxkux Is there a way to minimize that effect? I looked over the camera and it looks like there is no...
  7. fixit7

    Replaced NiMh battery in small solar light

    I replaced a 600 Mah NiMh battery in small solar light with a 2300 Mah since I had no 600 Mah hr batteries in my stock. It worked great for about a week, but then the light started blinking when it should be on steadily. Is it because the solar panel can not charge a battery with 4 times the...
  8. fixit7

    Corroded batteries in Blood pressure monitor

    This is a picture of my blood pressure monitor battery compartment. I used 2 aa alkaline batteries and 2 NiMh batteries. (I now know why they tell you not to mix batteries) The alkaline batteries corroded badly, while the NiMh batteries seem to be corrosion free. The top left side terminals...
  9. fixit7

    Solder flux uses and solder

    Solder paste uses and solder I recently received this and am learning about what applications it is good for. https://imgur.com/3pGTm0a I put a small amount on a project board and the solder seemed to adhere better. I am using up some old RS solder that has the paste already in it, though it...
  10. fixit7

    [SOLVED] Lubrication coaxial connector

    It's hard to unscrew the coaxial cable from the antenna. Is there something that can make that easier and minimize corrosion? I think there is corrosion occurring on the aluminum "arms" of the antenna as well.
  11. fixit7

    Dirty circuit board causing failure

    This is a wired controller for my computer audio system. It stopped working. It uses a soldered on switch and green indicator led light. It had a lot of white material around the solder points. I cleaned it with contact cleaner and warm soapy water. And GENTLY scraped away the corrosion using...
  12. fixit7

    Wireless door bell Sender not working

    Diagnose circuit board issue I am trying to diagnose why the door chime no longer works. The receiving unit sounds the various melodies. The battery voltage is ok. I have thoroughly cleaned the circuit board. The led lights up when the switch is pressed. Any other things to try next...
  13. fixit7

    Elementary questions

    I saw some of the questions posted in the Elementary Questions. They do not look elementary to me. These are some of the things I am learning and doing. Soldering and desoldering chips,resistors, etc. Wiring outlet boxes, extensions cords, replacing switch in a 30+ yr old bench grinder.

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