Re: relay board

john larkin <jl@glen--canyon.com> wrote:

On Wed, 26 Mar 2025 17:13:57 +0100, Lasse Langwadt <llc@fonz.dk>
wrote:
 

On 3/24/25 16:05, bitrex wrote:

On 3/24/2025 10:33 AM, john larkin wrote:

 
Here's another PCB:
 
https://www.dropbox.com/scl/fi/yxqdj418jx1ttuusqqehg/P946_Relays_A11.jpg?rlkey=hxshyt4mze59k31xpnsi3bfzc&raw=1
 
I figured we could have a relay board in our modular power system, and
my PCB layout guy had time, so I did one.
 
Then I figured that instead of fuses to protect the contacts and PCB
traces, I could use Hall sensors and drop out a relay if the current
exceeds 8 amps. Then I figured I may as well report the currents to
users. And why not voltage too? Then  it became a programmable circuit
breaker module. With average and RMS voltage and current and power
measurement and waveforms.  And programmable ganging. And plugin fuses
for bussing. Somebody stop me.
 

 
Better is the enemy of the good

 
 
more like enemy of "good enough" aka. done

 
Done is an important engineering virue.
 
If a bit of hardware could be applied with some code, it may well be
worth putting on a board. Some customer might want a feature and it
could be added quickly.
 
Lots of people make electronic programmable circuit breakers, but
generally don't include measurements or waveform acquisition. So why
not? I have embarassing amounts of whitespace on this PCB.
 
 
 
 
 
 

I can see how having a record of events prior to the “breaker” opening
could be useful.

--
piglet