My hand soap dispenser started to get slower and slower, even with fresh batteries. So I decided it was time to open it and see what was wrong.
Even with hand pumped foam dispensers, the fine metal or nylon mesh used to add the final layer of creaminess to the foam is prone to blocking over time with waterborne "stuff" (possibly organic).
It's nice that this unit is actually serviceable, with both the pump and the schmoo-plumper suited to complete disassembly for cleaning.
Quiescent current of this unit is around 2mA due to its need to continuously pulse the infrared LED. The microcontroller will turn the LED on then check the voltage from the photodiode and then turn the LED off again. It is usually only lit for as long as needed to get the reading.
When it detects a sudden increase of infrared light reflected, it runs the schmoo-pump briefly to dispense the creamy schmoo.
If you enjoy these videos you can help support the channel with a dollar for coffee, cookies and random gadgets for disassembly at:-
http://www.bigclive.com/coffee.htm
This also keeps the channel independent of YouTube's advertising algorithms allowing it to be a bit more dangerous and naughty.
#ElectronicsCreators

17 thoughts on “Fixing a faulty schmoo pump”
  1. Avataaar/Circle Created with python_avatars Austin D says:

    Robot jizz. That's going into the vernacular.

  2. Avataaar/Circle Created with python_avatars John Bache says:

    By driving the positive led feed from the mcu pins, it avoids any rogue flashes of light as the mcu boots up and might toggle the output pins as they are initialised?

  3. Avataaar/Circle Created with python_avatars fipz AV says:

    Eneloop AA are 1.2v rather than 1.5v – .9v down. Surely that slows it down a little?

  4. Avataaar/Circle Created with python_avatars A Lobo with ADHD says:

    Thumbnail still looks like something you’d use to wash your junk with.

  5. Avataaar/Circle Created with python_avatars Gary Seven says:

    Nice thumbnail, I actually expected to see a product called "JIZZMATIC 69".
    Then I remembered your sense of humour. 🤔
    Good to see that it's now Jizzing more effectively.

  6. Avataaar/Circle Created with python_avatars Jeremy L. says:

    The thumbnail. I just had to watch this.

  7. Avataaar/Circle Created with python_avatars Jawst A says:

    Can I say willy?

  8. Avataaar/Circle Created with python_avatars 12 Villages says:

    Getting active drain on this thing even when it is not ON. I have a 5056 8pin charger chip instead of the lth7.

  9. Avataaar/Circle Created with python_avatars Bartok Jaruzelski says:

    11.20 "Let's knock one out, shall we?" ☺♥☺♥☺♥☺♥☺♥

  10. Avataaar/Circle Created with python_avatars darkconsole says:

    clicked for the jizzmatic 69, stayed for the free mechanical engineering degree.

  11. Avataaar/Circle Created with python_avatars Jeff London says:

    "Robot Jizz" ……best line ever…….

  12. Avataaar/Circle Created with python_avatars Eric Ray says:

    Judging by the thumbnail I thought you were repairing a jack off machine… false advertising!

  13. Avataaar/Circle Created with python_avatars Andy XoX says:

    Wow, I just realised my life is incomplete due to not having a battery operated soap dispenser … 😔😔😔

  14. Avataaar/Circle Created with python_avatars Ewen Flint says:

    Re being hard to clean: once while putting "squirty cream" on a dessert and noting a weird taste, I took off the nozzle and noted a black fungal growth on the inside

  15. Avataaar/Circle Created with python_avatars michel Guevara says:

    I must say, I was a little worried about clicking on this , clive, I wasn't sure what you meant exactly by 'creamy schmoo pump'..

  16. Avataaar/Circle Created with python_avatars Halojen says:

    For anybody who's here because their dispenser stopped producing the robot jizz: DON'T USE PEARLESCENT SOAP.
    The shiny particles are just small enough to get through the first gauze but too big to get through the second one. I found that out the hard way. I don't think it's what caused Clive's one to die, because his soap doesn't seem to be pearly, but mine clogged almost immediately.

  17. Avataaar/Circle Created with python_avatars Kevin Chamberlain says:

    Interesting discussion of a fucking useless item.

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