Hot Water Boost Pump Flow Switch Teardown
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- เผยแพร่เมื่อ 27 เม.ย. 2020
- A look at what's inside a cheap Chinese flow switch.
The main electronic component is a TRIAC (not a "transistor", as I incorrectly say in the video). The magnetic reed switch puts a low voltage, low current signal on the TRIACs gate, via the resistor. This voltage switches the TRIAC on. - วิทยาศาสตร์และเทคโนโลยี
Thanks for this video. I have a 12VDC vane water pump without any on/off pressure control. If this was a purely mechanical switch internally, I could use this switch. But with the electronic components inside, I can't trust it to work from the 12VDC.
Yes, not an ideal switch for 12V, though you could modify it to just use the reed switch. This might be OK depending on how much current you need to control. Another option might be to use a Hall effect turbine flow meter. Cheap and wouldn’t need much extra to control 12V via a mechanical relay, or an SSR. www.ebay.co.uk/itm/172805656873 Good luck 🙂
Thank you, i was searching about this product.
Glad that it helped 🙂
I'm trying to diagnose one of these and I was expecting a hall sensor or the like. I was surprised to find that this was fed AC power, not 5V DC.
Yes, I was surprised too. I suppose it must be cheaper. Well proven and reasonably reliable as well.
@@Greeves also given there's only the two wires, my ignorance on AC must be showing as I'm not understanding how it is switching...
Oh nix that. As I typed the above out I realized that the two wires aren't hot and neutral but both are hots? The flow sensor is in series, not in parallel.
The majority of my knowledge has been in the realm of working on ESC's, specifically ebike controllers mostly. I'm used to expecting a signal wire more than a straight up on/off power switch for an automatic controller.
@@zalafinari I think that what I called a “transistor” is actually a triac. The resistor drops the voltage (& limits the current) through the reed switch and onto the gate of the triac, turning it on.
good ! thanks
Nice
Hello. actually the wire which is connected to the terminals of the transistor of the flow switch, and now I dont know which wire to connect with which terminal. can you help with that.
Hi. It’s been a while since I made this video and I threw away the switch straight after making it. Thinking about it again, the three pin component (TO package) is most likely a triac. This would allow a low current flowing through the reed switch & resistor to control the higher current AC to the motor. The leg of the Triac that had/has the resistor/reed switch attached would be the gate. The other 2 pins would attach to the live mains & pump supply. If you can see any markings on the TO package you could maybe find a data sheet for the component & confirm its type & pin-out. Presumably you’ve managed to dig out the resin encapsulating the electronic components in the flow switch, though I’m not sure why you would do this; better & safer to buy a new flow switch (?)
Hi. Can we connect 220v ac directly to the flow switch and then one lead to the mains of the motor and join the neutral to the main 220v supply?
Hello. The short answer is that I don't know - so whatever you try is at your own risk. If it was me, I'd carefully try it with 220V & see what happens. I think that what I called a "transitor" in the video is actually a gate-turn-off thyristor (similar to a TRIAC). When the reed switch is closed it probably puts a low voltage on the GTO gate, via the resistor, turning it on. It will turn off when the reed switch opens. I didn't take the motor apart to see what's inside but the simplest , cheapest, most likely assumption is that it contains no electronics and is just mains wiring to the 3 position switch, motor, float switch connector & power lead. You could check this by measuring the voltage on the motor's float switch connector pins (with the float switch disconnected). Do this first; if there’s 220V on at least one pin, you’re probably OK to use the switch as you describe. Good luck :)
@@Greeves thank you🙏
Can I have circuit daigram of this unit and parts name pls
Hi. The flow switch came attached to a boost pump that I bought of eBay. I didn't need the switch, so took it apart & then threw it away. I don't know the part number but they seem fairly common. The pump below (see link) comes with one for example.
As for the circuit, I think that the "transistor" device is actually a TRIAC. The magnetic reed switch will apply a small voltage to the gate, which turns the main electicity power flow on/off. This YT video explains:- th-cam.com/video/cyeEzU6KmzY/w-d-xo.html I hope this helps.
www.ebay.co.uk/itm/314379894534?hash=item4932807f06:g:SAcAAOSwduhgtcev&amdata=enc%3AAQAIAAAAwNzGd%2FdQnV1ZthNt9w4yor6qF9wwE7wsxxa7%2FcNIKoAPuVECrXF0%2F7a%2FCtR6VnZpkZ8RcDCB1pzr5rCqbCppc270xdyV4NnXCKqeUEOhdCWKY%2F%2FCq4mmFLNXfxSrGq7gNxdUya86mJ1gyfefC%2BJNb7kNi0uCbJCgF5l66RaAr%2Fl95Vynky%2BmJ93tI70uTxbkn8TF18AHUX9ig2iPHlls3w0sYQWMjEKAu3dnLvgHzNx9pQZ39580dO0MFNKHId9Hfw%3D%3D%7Ctkp%3ABk9SR5Kv0Jj1YQ
Speak up please!
Thanks for taking the time to comment. Please could you let me know: was it too quiet even with the volume turned up, or just quieter than other TH-cam videos? I’m trying to work out how best to improve things.
I agree: Please use your "announcer voice" for YT videos. Thanks
good ! thanks
Welcome!