Isolated power supplies
This project may at first glance appear to have nothing to do with the Picaxe world. In fact, if you are just starting out in electronics or just a casual hobbyist, right now you’re probably thinking “Meah… power supplies, so what”. However, if you are an engineer/techie with a few years experience working in heavy industry or robotics under your belt, isolation is not a conversation we need to have (you’ve already been bitten by that dog).
Alright… a few examples to show you why the little boogers in the attached .pdf may be of some value for you:
01 You just bought a new amp display for your shiny new boat’s trolling motor. You’ve wired it up & the amp readout is
way out of whack. Just double-checked the wiring, no screw-ups. Now you go back to the installation diagram & there it is in small print: “The amp display system must be powered from a source separate from the motor power”. You gotta’ be kidding! I gotta’ buy another battery!
02 You just installed a nice industrial pressure sensor on your solar water control system, then you read the spec. sheet
“requires +24vdc power for 4...20mA signal”. Oh no, my control system runs on +12vdc! Oh no!
03 Just wired up that new analog-to-digital panel, time to connect the power supply. Wait a minute… on-board op-amps
need -12vdc. Dammit! I wanted all this stuff to run off my +12v battery! I ain’t got no room on this damn thing for another power supply! Bad enough, but my ma-in-law’s poodle won’t get off my leg! Uh-oh… probably shouldn’t have kicked the dog.
04 My little Picaxe controller goes bonkers every time I connect that shunt! Oh no… not that stupid isolation thing again.
etc……
Ok… let’s read the attached .pdf & see if we can’t make a few light bulbs come on.
Problem 01: I need an isolated power supply for my amp readout
problem 02: I need a +24v supply
problem 03: I need a +12v/-12v supply
problem 04: I need an isolated +5v supply for my Picaxe controller
Now, just like most other stuff in technology, there’s always a few caveats:
The lil’ power supplies shown below won’t supply a lot of current (e.g. the +12v output can only source ~80mA)
Can’t drive a lot of capacitance
The B...S-1W modules can all use the same lil’ board. Although, the suggested capacitor specs vary for each module, I have used all 10uF caps with all & they work just fine (I had a drawer full of the 10uF caps).
This project may at first glance appear to have nothing to do with the Picaxe world. In fact, if you are just starting out in electronics or just a casual hobbyist, right now you’re probably thinking “Meah… power supplies, so what”. However, if you are an engineer/techie with a few years experience working in heavy industry or robotics under your belt, isolation is not a conversation we need to have (you’ve already been bitten by that dog).
Alright… a few examples to show you why the little boogers in the attached .pdf may be of some value for you:
01 You just bought a new amp display for your shiny new boat’s trolling motor. You’ve wired it up & the amp readout is
way out of whack. Just double-checked the wiring, no screw-ups. Now you go back to the installation diagram & there it is in small print: “The amp display system must be powered from a source separate from the motor power”. You gotta’ be kidding! I gotta’ buy another battery!
02 You just installed a nice industrial pressure sensor on your solar water control system, then you read the spec. sheet
“requires +24vdc power for 4...20mA signal”. Oh no, my control system runs on +12vdc! Oh no!
03 Just wired up that new analog-to-digital panel, time to connect the power supply. Wait a minute… on-board op-amps
need -12vdc. Dammit! I wanted all this stuff to run off my +12v battery! I ain’t got no room on this damn thing for another power supply! Bad enough, but my ma-in-law’s poodle won’t get off my leg! Uh-oh… probably shouldn’t have kicked the dog.
04 My little Picaxe controller goes bonkers every time I connect that shunt! Oh no… not that stupid isolation thing again.
etc……
Ok… let’s read the attached .pdf & see if we can’t make a few light bulbs come on.
Problem 01: I need an isolated power supply for my amp readout
problem 02: I need a +24v supply
problem 03: I need a +12v/-12v supply
problem 04: I need an isolated +5v supply for my Picaxe controller
Now, just like most other stuff in technology, there’s always a few caveats:
The lil’ power supplies shown below won’t supply a lot of current (e.g. the +12v output can only source ~80mA)
Can’t drive a lot of capacitance
The B...S-1W modules can all use the same lil’ board. Although, the suggested capacitor specs vary for each module, I have used all 10uF caps with all & they work just fine (I had a drawer full of the 10uF caps).
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