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by y2kvette
Tue Sep 08, 2020 3:52 pm
Forum: Automation, sensing and robotics
Topic: Cat Home DIY Q&A - Solenoid Valve How To
Replies: 27
Views: 7392

Re: Cat Home DIY Question - How to Use Solenoid Valve

Puro-XD-12 Solenoid Valve Newbie Experiments Now I am using the following old solenoid test rig to test the new solenoid valve. RE: CAT FEEDER DIY - HOW TO USE SOLENOID tlfong01 2019Jan17 https://www.raspberrypi.org/forums/viewtopic.php?f=37&t=230984&start=25#p1417151 ...
by tlfong01
Tue Mar 05, 2019 2:23 pm
Forum: Automation, sensing and robotics
Topic: Connecting electromagnet to pi
Replies: 94
Views: 13112

Re: Connecting electromagnet to pi

... is that my results are not reliable and not repeatable. I can only said that the average inductance is very very roughly 5mH . Measuring Solenoid Inductance - Unsatisfactory Results I measured 4 solenoids, from 0.8N to 20N. The results is not satisfactory at all. Two solenoids find Vr ...
by tlfong01
Tue Mar 05, 2019 12:59 pm
Forum: Automation, sensing and robotics
Topic: Connecting electromagnet to pi
Replies: 94
Views: 13112

Re: Connecting electromagnet to pi

... conclusion is that my results are not reliable and not repeatable. I can only said that the average inductance is very very roughly 5mH. Measuring Solenoid Inductance Now I am moving on to solenoid inductance measurement, and see if it is different from measuring electromagnets, and perhaps finding ...
by tlfong01
Sun Mar 03, 2019 1:53 am
Forum: Automation, sensing and robotics
Topic: Connecting electromagnet to pi
Replies: 94
Views: 13112

Re: Connecting electromagnet to pi

... might seem silly but I'm a bit confused by the phrasing. Does this mean I don't have to use an external power supply and just connecting the solenoid to the board will supply it with enough voltage? Relay Newbie Total Confusion Guide Well, perhaps you can give me a link to the Amazon/AliExpress/eBay ...
by jadel
Sat Mar 02, 2019 10:08 pm
Forum: Automation, sensing and robotics
Topic: Connecting electromagnet to pi
Replies: 94
Views: 13112

Re: Connecting electromagnet to pi

... might seem silly but I'm a bit confused by the phrasing. Does this mean I don't have to use an external power supply and just connecting the solenoid to the board will supply it with enough voltage?
by tlfong01
Thu Feb 28, 2019 2:57 pm
Forum: Automation, sensing and robotics
Topic: Connecting electromagnet to pi
Replies: 94
Views: 13112

Re: Connecting electromagnet to pi

... to calculate . This is the part I found interesting. I am thinking of googling more readings and try to begin with calculating the inductance of solenoid or electromagnet which is useful for selecting a flyback diode. Inductance Stuff - Hard to Understand, But Very Easy to Google, Cut, Paste, ...
by tlfong01
Wed Feb 27, 2019 2:11 pm
Forum: Automation, sensing and robotics
Topic: Connecting electromagnet to pi
Replies: 94
Views: 13112

Re: Connecting electromagnet to pi

... Sine/Triangle/Rectangular Wave Sig Gen Now I am trying to use the cheapy US$3 sig gen to find the inductance of solenoids, solenoid valves, and electromagnets. ICL8038 Signal Generator Medium/Low Frequency 10hz-450khz Triangular/Rectangular/Sine Wave Generator ...
by tlfong01
Wed Feb 27, 2019 1:44 pm
Forum: Automation, sensing and robotics
Topic: Connecting electromagnet to pi
Replies: 94
Views: 13112

Re: Connecting electromagnet to pi

... to calculate. This is the part I found interesting. I am thinking of googling more readings and try to begin with calculating the inductance of solenoid or electromagnet which is useful for selecting a flyback diode. PS - I found your post easy to follow, because you speaks middle school physics ...
by tlfong01
Wed Feb 27, 2019 8:07 am
Forum: Beginners
Topic: Resistors and MOSFETs and fire-prevention, oh my
Replies: 156
Views: 19806

Re: Resistors and MOSFETs and fire-prevention, oh my

DSP Sig Gen 1Hz 50% duty cycle driving motor and solenoid, and 1kHz motor only 1kHz signal input to Power MOSFET IRL540N, Rg 470Ω, Rgs 4k7, Vcc 12V, Rload 5Ω 20W Now I tested a 5 resistor 20W, and found everything OK. Power MOSFET IRL540N, Rg 470Ω, ...
by tlfong01
Wed Feb 27, 2019 8:02 am
Forum: Beginners
Topic: Resistors and MOSFETs and fire-prevention, oh my
Replies: 156
Views: 19806

Re: Resistors and MOSFETs and fire-prevention, oh my

tlfong01 wrote:
Tue Feb 26, 2019 3:01 pm
DSP Sig Gen 1Hz 50% duty cycle driving motor and solenoid, and 1kHz motor only

1kHz signal input to Power MOSFET IRL540N, Rg 470Ω, Rgs 4k7, Vcc 12V, Rload 5Ω 20W

Now I tested a 5 resistor 20W, and found everything OK.

...
by tlfong01
Wed Feb 27, 2019 4:48 am
Forum: Automation, sensing and robotics
Topic: Connecting electromagnet to pi
Replies: 94
Views: 13112

Re: Connecting electromagnet to pi

... refer to my power MOSFET switch schematic below. You can just replace the MOSFET by a relay, and everything "should" work. Controlling Solenoid By High Level Trigger 5V Relay KY019 Or check out my old post below: Relay KY019 Switching Solenoid https://www.raspberrypi.org/forums/viewtopic.php?f=37&t=230984&p=1417588&hilit=schottky#p1417740 ...
by tlfong01
Tue Feb 26, 2019 3:01 pm
Forum: Beginners
Topic: Resistors and MOSFETs and fire-prevention, oh my
Replies: 156
Views: 19806

Re: Resistors and MOSFETs and fire-prevention, oh my

... fried . I removed the varister and replaced another IRL540N and found everything OK again. DSP Sig Gen 1Hz 50% duty cycle driving motor and solenoid, and 1kHz motor only https://youtu.be/1cysjRcF40g (youtube) No substantial ringing at Vin, and no flyback spikes noticeable. Next step is to ...
by tlfong01
Sat Feb 23, 2019 2:08 am
Forum: Beginners
Topic: RPI Zero W multiple sensors
Replies: 27
Views: 8277

Re: RPI Zero W multiple sensors

... such as Rpi org or stackexchange, or hobbyists project competitions, such as by E14 and RS. In case your microgreen project makes use of water solenoid valves and ESP8266 WiFi, you might like to read the following invitation from the Element 14 community. These competitions are much easier ...
by tlfong01
Thu Feb 21, 2019 3:58 am
Forum: Beginners
Topic: Resistors and MOSFETs and fire-prevention, oh my
Replies: 156
Views: 19806

Re: Resistors and MOSFETs and fire-prevention, oh my

... big guy and switched on power, but motor not turning. I removed the big motor and replaced it by the original small guy. But nothing happened. The solenoid and motor no longer responded. So now I am in big trouble! :( Resettable PPTC Fuse vs Circuit Breakers With Manual Reset Button I found the ...
by tlfong01
Wed Feb 20, 2019 12:25 pm
Forum: Beginners
Topic: Resistors and MOSFETs and fire-prevention, oh my
Replies: 156
Views: 19806

Re: Resistors and MOSFETs and fire-prevention, oh my

... by IR L 540 or similar logic level MOSFET solves the problem. https://youtu.be/eXIxTtvtLaQ ( youtube logic level power MOSFET driving motor and solenoid ) Third Generation Power MOSFET IRL540N (Vgs(th) = 1.87V) Testing Plan The new toys arrived this morning. So I will focus on testing this third ...
by tlfong01
Tue Feb 19, 2019 4:53 am
Forum: Beginners
Topic: Resistors and MOSFETs and fire-prevention, oh my
Replies: 156
Views: 19806

Re: Resistors and MOSFETs and fire-prevention, oh my

... Yes, IRF540 replaced by IRL540 or similar solves the problem. https://youtu.be/eXIxTtvtLaQ (youtube logic level power MOSFET driving motor and solenoid) Power MOSFET IRL540N Hacking Diary Last evening I ordered 50 pieces of IRL540N at ¥1.20/ea to be delivered by SFexpress. Now they are on the ...
by tlfong01
Mon Feb 18, 2019 8:18 am
Forum: Beginners
Topic: Resistors and MOSFETs and fire-prevention, oh my
Replies: 156
Views: 19806

Re: Resistors and MOSFETs and fire-prevention, oh my

Power MOSFET driving big solenoids Now I am checking out if the power MOSFET can drive big solenoids. https://www.raspberrypi.org/forums/viewtopic.php?f=37&t=230984&start=25#p1417772 Driving Big Motor Mabuchi RS-540SH 12VDC Motor ...
by tlfong01
Mon Feb 18, 2019 7:01 am
Forum: Beginners
Topic: Resistors and MOSFETs and fire-prevention, oh my
Replies: 156
Views: 19806

Re: Resistors and MOSFETs and fire-prevention, oh my

... 1.75 * 0.05 = 0.09W = 0.1W . My conclusion a current switch of logic 3V0 level control of 1.75A, 90mΩ , 0.1W is good enough for general motor and solenoid applications. ...
by tlfong01
Mon Feb 11, 2019 2:18 pm
Forum: Beginners
Topic: RPI Zero W multiple sensors
Replies: 27
Views: 8277

Re: RPI Zero W multiple sensors

... with capacitive moisture sensor (CSMO v1.2) - 6. sensor control the solenoid valve to water the pod with relay 7. MCP3008 to convert it to digital ... can search the forum for my relevant old posts using the keywords "tlfong01" + "hx711" + "mcp23017" + "esp3266" ...
by tlfong01
Sun Feb 10, 2019 12:22 pm
Forum: Beginners
Topic: Resistors and MOSFETs and fire-prevention, oh my
Replies: 156
Views: 19806

Re: Resistors and MOSFETs and fire-prevention, oh my

... quite a long way in power electronics. It was almost 6 months ago I joined a discussion on how to detect 24VDC, and then how to drive a buzzer and solenoid, then solenoid valve, then EEG, and ECG, all of which has much to do with electricity and magnetism, which I learned in middle school physics. ...
by tlfong01
Sun Feb 10, 2019 10:09 am
Forum: Beginners
Topic: Resistors and MOSFETs and fire-prevention, oh my
Replies: 156
Views: 19806

Re: Resistors and MOSFETs and fire-prevention, oh my

4. ...somebody has the same problem as me. Even when I use 9V batteries for all this (no Rpi...taking it back to simple for debugging), the solenoid turns on just once. I have to remove power source from it to reset everything back. 5. And then the recommendation comes out to add a capacitor ...
by tlfong01
Thu Jan 31, 2019 4:06 am
Forum: Automation, sensing and robotics
Topic: MCP23017 Learning Notes
Replies: 34
Views: 4585

Re: Cat Home DIY Q&A - Solenoid MCP23017 How To

tlfong01 wrote:
Wed Jan 30, 2019 2:01 pm

MCP23017 Basic Test Program

I am writing a MCVO PCA9865 program, using the most updated MCP23017 MCVO program as a template, the old PCA9865 program to cut down.

https://penzu.com/p/10f0caed
by tlfong01
Wed Jan 30, 2019 2:01 pm
Forum: Automation, sensing and robotics
Topic: MCP23017 Learning Notes
Replies: 34
Views: 4585

Re: Cat Home DIY Q&A - Solenoid MCP23017 How To

tlfong01 wrote:
Wed Jan 30, 2019 1:48 pm
PCA9685 Getting to know the registers

PCA9685 An Old Program 2017 Listing

Now I am reading an old program to refresh my memory.

https://penzu.com/p/05d7cee9
by tlfong01
Wed Jan 30, 2019 1:48 pm
Forum: Automation, sensing and robotics
Topic: MCP23017 Learning Notes
Replies: 34
Views: 4585

Re: Cat Home DIY Q&A - Solenoid MCP23017 How To

tlfong01 wrote:
Wed Jan 30, 2019 8:43 am

PCA9685 Getting to know the registers

https://penzu.com/p/4e0b5b3c
by tlfong01
Wed Jan 30, 2019 8:43 am
Forum: Automation, sensing and robotics
Topic: MCP23017 Learning Notes
Replies: 34
Views: 4585

Re: Cat Home DIY Q&A - Solenoid MCP23017 How To

tlfong01 wrote:
Wed Jan 30, 2019 7:27 am
https://penzu.com/p/94ad8ffc
Now I have placed 2 PCA9865 on a proto board and i2cdetect OK.

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