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You think Sayal is a Good source? I had some dealings with them here in Burlington Ontario, the other 2 mentioned, not sure now with cross border shopping from the U.S and new Duties etc.
Need circuit design help with model torpedo launcher
- Thread starter JureGeorge#1
- Start date
OH forgot to ask reg the 1M pot, what physical size pot should I look for to fit onto the circuit board? Picture sample please.
Another version using a reed switch.
Zero current when magnet near and motor not running.
Reed Switch
Zero current when magnet near and motor not running.
Reed Switch
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Thank you both for your help with this circuit.
I will be getting enough parts for One Proto board test circuit of Post#64. Off to Sayal Wed. for parts.
Did you have a chance to put together the above test circuit? Was curious if it would handle at least 2A like the AO3400 Mosfet. I know under starin the DC motor can draw higher current briefly. Please let me know. Thanks again.
We need to know how much current the motor needs. Then we select a MOSFET to satisfy those requirements.
It also important about the the gate voltage and the Rds.
From my research I find those mini motors on average draw around 120ma on 3.7 volts and several more hundred if stalled.
I don't see any debate about not using the AO3400.
It's also important not to exceed the current rating of the reed switch.
From my research I find those mini motors on average draw around 120ma on 3.7 volts and several more hundred if stalled.
I don't see any debate about not using the AO3400.
It's also important not to exceed the current rating of the reed switch.
I think, have NOT tested the actual motors yet, still in transit, the motor under load would be at least 1A so if I understood the past messages, the AO3400 MOSFET has 4A capability? IF so, that is More than enough.
You are the best hioto
The largest component is the trimpot. If you can perform tests to determine the desired run time, a fixed resistor will make the board a lot smaller. I can get the board down to 10 x 10 mm.
I don't have MOSFET in SMD packages. I used whatever I have at hand. I even have 0603 size SMD resistors.
This is a test board, 10 x 20 mm.
With components:
I don't have MOSFET in SMD packages. I used whatever I have at hand. I even have 0603 size SMD resistors.
This is a test board, 10 x 20 mm.
With components:
Wow, Mr. Chips a 10x20mm board is PERFECT for my wishes. I would like to try and use a 1M Pot so that I can have the option to adjust the run time. How thick do you think the board is with components ALL mounted?
This trimpot is about 2.5 mm in thickness. Adding about 2 mm for the board gives about 4.5 mm thickness.
https://www.bourns.com/docs/Product-Datasheets/pvg3.pdf
https://www.bourns.com/docs/Product-Datasheets/pvg3.pdf
That is exactly what I need. I am going ahead and getting surface mounting components in 0805 size as well as the AO3400 MOSFET and the 1M Pot. If you can go ahead with the circuit board creation, please let me know. Thanks again for your Time / Help with this.
I went to my local parts suppliers and both had a few BUT NOT ALL in stock. Was told I needed large quantity order for them to order in; my local Sayal and another small shop, so I ordered through ebay, the entire lot. A bit more time BUT prices were good.
Any chance I can ask you about the circuit board above, it is One sided or Two. It`s size: 10mm x 20mm?
Would a 2N7002 be o.k to use in place of 2N7000 ? For both Q & Q2 ?
The board is 10 x 20 mm, single sided.
