Solid state PDM or power distribution module.

javajoe79

javajoe79

Fabricator
Is anyone using one of these for this application yet? Seems like an untapped resource. I use them occasionally in the custom car/race cars that I build. Many of them have limited inputs and or can bus control only but recently I came across an option that offers fully analog inputs for switching etc... Hardwire in the UK makes a few different units. I am probably about to buy the PDM 15 unit from them. https://www.hardwire-electronics.co.uk/product-page/pdm-15

With this setup you eliminate all relays and fuses. Each output and input is programmable in a variety of ways. You can set current limits on each output, setup inputs as either ground or 12v trigger, momentary, blinkers etc.

My Isuzu NPR is a completely custom build and I am going to strip out the factory cab harness and build a new setup with this PDM as the core. It will power everything related to the cab, drivetrain and chassis lighting and I'll probably have a few extra circuits for future use. Once the camper is done I'll probably use another PDM for all of the camper power needs.

There are a number of PDM options out there from fairly affordable small units from Rowe Electronics https://www.rowe-electronics.com/amplink
to many thousands of dollars, high end racing units from Motec https://www.motec.com.au/pdm15/pdm15overview/

I just thought I would put this out there to start a discussion and see if anyone else is using these.
 
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Rando

Explorer
A lot of people are using these, just by less technical names. Thinks like sPOD, Switch Pros, Aux Beam and dozens more are all 'Solid State PDMs'.

If you are so inclined, you can even make your own - these are what many of them are using, $4 per channel:

BTS50025-1TEA - Infineon Technologies

The BTS50025-1TEA is a 2.5mΩ single channel Smart High-Side Power Switch, embedded in a PG-TO-252-5-11 package, providing protective functions and diagnosis.
www.infineon.com www.infineon.com
 
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javajoe79

javajoe79

Fabricator
Rando said:
A lot of people are using these, just by less technical names. Thinks like sPOD, Switch Pros, Aux Beam and dozens more are all 'Solid State PDMs'.

If you are so inclined, you can even make your own - these are what many of them are using, $4 per channel:

BTS50025-1TEA - Infineon Technologies

The BTS50025-1TEA is a 2.5mΩ single channel Smart High-Side Power Switch, embedded in a PG-TO-252-5-11 package, providing protective functions and diagnosis.
www.infineon.com www.infineon.com
Click to expand...
The spod I installed a couple years ago definitely wasn't solid state. Good to see they have updated. That thing was kind of lame for the price. Good point though. I forgot about those as they seemed more for accessories than for fully wiring a vehicle. Aux beam looks like it just uses solid state relays but still has fuses.
 
R

Rando

Explorer
I still think the sPOD is kind of lame for the price. The solid state MOSFET switches are cheaper and easier for a manufacturer than relays/fuses. But I do think it has the same 'features' as an official 'PDM' such as configurable current limits and the like.

These things are pretty simple to build and program so I would be shocked if there were not an arduino based project to DIY one for a fraction of the cost.
 
J

john61ct

Adventurer
Very interesting, CAN control allows unlimited possibilities!

Looks like many BMS functions for House bank protection could be handled, with greater confidence in reliability

Plus staged "battery protection" of the House bank, shutting down loads as it gets depleted, least essential circuits first, so the critical safety / navigation circuits can operate much longer.

Maybe even charging controls when multiple sources are available.

Help me out here on circuit monitoring, current draw reporting is obviously inherent, but is voltage sensing on the output circuits also common?

Also, how about current **limiting** rather than just hiccup/latching protection? Say a target battery wanted to draw 30A but I wanted to allow it to just get a 20A feed

not getting cut off, but actually reducing the current allowed while maintaining the voltage?

If no PDM does this, what sort of device does? that could be incorporated, between the PDM output and the target load input...
 
R

Rando

Explorer
john61ct said:
Very interesting, CAN control allows unlimited possibilities!

Looks like many BMS functions for House bank protection could be handled, with greater confidence in reliability

Plus staged "battery protection" of the House bank, shutting down loads as it gets depleted, least essential circuits first, so the critical safety / navigation circuits can operate much longer.

Maybe even charging controls when multiple sources are available.

Help me out here on circuit monitoring, current draw reporting is obviously inherent, but is voltage sensing on the output circuits also common?

Also, how about current **limiting** rather than just hiccup/latching protection? Say a target battery wanted to draw 30A but I wanted to allow it to just get a 20A feed

not getting cut off, but actually reducing the current allowed while maintaining the voltage?

If no PDM does this, what sort of device does? that could be incorporated, between the PDM output and the target load input...
Click to expand...

Remember that CAN is just an interface protocol, you would need a device that runs the software that implements the BMS functions and sends the CAN bus messages to the 'PDM' to tell it to turn on/off certain channels, or to ask it what the battery voltage or current is on a certain channel.

These units are typically designed to connect to a power source (the battery/alternator) and then connect loads to each output channel. They provide current monitoring (and programmable limits) on each output channel, and the input (power source) voltage. There is not really any point in voltage sensing on the output channels, when the channel is off, the voltage is zero and when the switch is on the voltage is essentially the same as the power source.

Controlling the current is whole different concept, you cannot do that with a PDM as the current depends as much on the load as it does on the source. A programmable DC-DC converter is the best option for trying to control currents.

Generally speaking, you cannot connect a battery or other power source to an output channel - they are unidirectional, power flows in from the source connected to the input, and out to the various output channels.
 
javajoe79

javajoe79

Fabricator
Well I just ordered the PDM 15 from Hardwire. It's in stock stateside so I'll have it soon. I should be able to get it wired up in a minimal capacity pretty quickly. I'll document it in my build thread. I'm excited to get rid of all the unnecessarily complicated wiring that the NPR has now. Plus this will all be brand new and much more robust/weatherproof.
 
J

john61ct

Adventurer
Yes Arduino is well suited to CAN messaging output, and analog control signals as well of course, viva simplicity.

Rando said:
There is not really any point in voltage sensing on the output channels, when the channel is off, the voltage is zero and when the switch is on the voltage is essentially the same as the power source.
Click to expand...
Not when the loads are depleted batteries. With LI chemistries, you might start out at say 3.2Vpc and then stop at 3.45V or 4.15Vpc

But if a DCDC is required in between for current limiting anyway, a simple LVC on its input (PDM output) will do the job.

> Generally speaking, you cannot connect a battery or other power source to an output channel - they are unidirectional, power flows in from the source connected to the input, and out to the various output channels

I don't see why not, I certainly do not want any power to flow backwards towards their charge source, the power from those target batteries once charged would flow to their loads "downstream" only.
 
R

Rando

Explorer
john61ct said:
Yes Arduino is well suited to CAN messaging output, and analog control signals as well of course, viva simplicity.

Not when the loads are depleted batteries. With LI chemistries, you might start out at say 3.2Vpc and then stop at 3.45V or 4.15Vpc

But if a DCDC is required in between for current limiting anyway, a simple LVC on its input (PDM output) will do the job.

> Generally speaking, you cannot connect a battery or other power source to an output channel - they are unidirectional, power flows in from the source connected to the input, and out to the various output channels

I don't see why not, I certainly do not want any power to flow backwards towards their charge source, the power from those target batteries once charged would flow to their loads "downstream" only.
Click to expand...

I guess I am not really sure what you are thinking about using these for? Interfacing with individual cells? In which case a purpose built BMS would have to be a better and cheaper option.
 
R

Rando

Explorer
Hillbilly Heaven said:
Problem with Arduino is the inputs are limited to a max of 3.3 volts.
Click to expand...

That is usually not a problem. The solid state switches will take a 3.3V control signal, and inputs to the Arduino can either be divided down (analog) or buffered (digital). For CAN you need to add a CAN bus driver anyway.
 
J

Johncmng

Member
Rando said:
I still think the sPOD is kind of lame for the price. The solid state MOSFET switches are cheaper and easier for a manufacturer than relays/fuses. But I do think it has the same 'features' as an official 'PDM' such as configurable current limits and the like.

These things are pretty simple to build and program so I would be shocked if there were not an arduino based project to DIY one for a fraction of the cost.
Click to expand...


There is!!

SHIELD_BTS50025-1TEA | This board is intended to provide a simple, easy-to-use user interface for getting familiar with Infineon's High Side Switch BTS50025-1TEA on PC - Infineon Technologies

This board is intended to provide a simple, easy-to-use user interface for getting familiar with Infineon's High Side Switch BTS50025-1TEA running on PC
www.infineon.com www.infineon.com
 
R

Rando

Explorer
R

Rando

Explorer
Probably not. I don't think most automotive folks would use banana plugs for this application. If you wanted to do this for real you would likely want to make your own PCB layout using connectors and number of channels of your choice. But for someone looking to control their aux lighting and fridge, this would be a great start.

I think the take home point is that these are fairly simple devices.
 
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