This is an old PWM Module drawing. The idea is to create a PLC module that can handle 4,6 or 8 PWM channels with 12/24V and up to 3A. I know from testing of MC4X15A that this is very doable as soon as I solve the current sensor on the channels. The usage here is…
I just realized that my math around INA210 current sensing is wrong. I have dimensioned based on 15A design which is the average I expect from all 4 channels driving a single motor. Basically the input current. But, output current on a phase will be based on PWM. And if you use 50% duty you…
I have collected a few power MOSFET samples that I will be testing in due time. It exist other MOSFET’s, but these are selected due to a combination of package, cost and performance that make them interesting. IRFS3107 various packages and is rated 75V @ 160A. It is actually rated 195-230A, but looking at the…
Not so much to write home about, but adding the heat sink back on I turned it up to 5A on a single channel – no heat noticed. My new loads do their job consuming some 100W, but my 5A PSU reached it’s limit. This was 20% duty cycle, so actual phase current was 25A.…
I have removed the heat-sink on the pcture above and is testing on the one good channel I had left. Just using my fingers on the MOSFET’s I get to 3A without heat-sink. This is very promissing and indicate that I have suffered a bit bad numbers from bad MOSFET’s.
Update : 13 of 50 MOSFET’s might be ok after testing! I purchased 50 x IRF7862 MOSFET’s from Asia through AliExpress and while I usually am happy with what I buy here it happens that I get screwed by non-honest sellers. What some of them do is to pick rejected chips from the factory and…
This picture show my latest test upset. I am still only testing a single PWM channel on MC4X15A, but it has caused a few Challenges. I finally got hold of 100W resistors that can sustain heavier load and using a 4 Ohm 100W I can continue my testing without being concerned about the load melting…
One of the generic changes I have considered for some time is to replace my 2×5 pin SWD connector with a 1×5 pin Micro JST connector. These connectors use 1.27 pitch and you get plenty of ready made cables. Firstly I only use 1×5 pin anyway and usually find other solutions for debug UART. But,…
I am adding 2 CAN/USB Adaptors. The upper one is not galvanic isolated while the lower one is 2cm longer and uses ADM3053 which also makes the board ca 5-8.- USD more expensive. The MCU is STM32F105RB and the USB is full host or Device capable. The SN65HVD233 based one have a few Control functions…
I just realized that ADM3053 is NOT a 3.3V device. It says 5V or 3.3V on VIO, but VCC requires 5V. The schematics I have used is also wrong as it does not feed power to VIO at all. The example on the datasheet is very misleading in this case. Looking at ADM2583 that I…