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geekhack Community => Off Topic => Topic started by: tp4tissue on Tue, 13 September 2016, 12:22:51

Title: EEngineers halp Please, Power Supply question (non PC)
Post by: tp4tissue on Tue, 13 September 2016, 12:22:51
Not a PC power supply

So....

Buying a big'ol Linear..

It comes with 20amp on 50v


Now, the 5v, 12v or 24 volt rails cost extra.


I know I want the 5v for maybe an arduino or something.. 

But   12v vs 24v   Which one is more commonly useful


probably the 12v right ? (http://emoticoner.com/files/emoticons/onion-head/confused-onion-head-emoticon.gif?1292862495)
Title: Re: EEngineers halp Please, Power Supply question (non PC)
Post by: xtrafrood on Tue, 13 September 2016, 13:12:09
24v = proper 3D printr

The choice is yours. (I'm not an engineer btw - just so we're clear about that :-* )
Title: Re: EEngineers halp Please, Power Supply question (non PC)
Post by: tp4tissue on Tue, 13 September 2016, 13:14:50
24v = proper 3D printr

The choice is yours. (I'm not an engineer btw - just so we're clear about that :-* )

hahaha , no there's only gonna be 2 amps on the 24v rail..  it's for microcontrollers and such.. the 50v is for motors.
Title: Re: EEngineers halp Please, Power Supply question (non PC)
Post by: xtrafrood on Tue, 13 September 2016, 13:16:22
24v = proper 3D printr

The choice is yours. (I'm not an engineer btw - just so we're clear about that :-* )

hahaha , no there's only gonna be 2 amps on the 24v rail..  it's for microcontrollers and such.. the 50v is for motors.

Icky! Put it back tp!  :(
Title: Re: EEngineers halp Please, Power Supply question (non PC)
Post by: tp4tissue on Tue, 13 September 2016, 13:32:01
24v = proper 3D printr

The choice is yours. (I'm not an engineer btw - just so we're clear about that :-* )

hahaha , no there's only gonna be 2 amps on the 24v rail..  it's for microcontrollers and such.. the 50v is for motors.

Icky! Put it back tp!  :(

(http://emoticoner.com/files/emoticons/onion-head/hehe-onion-head-emoticon.gif?1292862507)
Title: Re: EEngineers halp Please, Power Supply question (non PC)
Post by: heedpantsnow on Tue, 13 September 2016, 13:37:19
I run 12v power supplies inside my espresso machines for lights, extra temp monitoring, etc.  Most computer peripherals (other than USB) use 12v, and obviously automotive stuff.  Arduino doo dads are often 5v.  24v for industrial logic and controllers.  PLC's and PID's commonly come in 12v and 24v flavors.  Hope that helps.
Title: Re: EEngineers halp Please, Power Supply question (non PC)
Post by: tp4tissue on Tue, 13 September 2016, 17:20:40
I run 12v power supplies inside my espresso machines for lights, extra temp monitoring, etc.  Most computer peripherals (other than USB) use 12v, and obviously automotive stuff.  Arduino doo dads are often 5v.  24v for industrial logic and controllers.  PLC's and PID's commonly come in 12v and 24v flavors.  Hope that helps.

Sup heedpants



I need ~500 watts for now,  (maybe more later down the road)

Now,  would there be a difference between the 1000watt coil vs a 600watt coil  in supplying 500 watts?

The rectifier on both supplies I believe is the same, with identical chip'n'capacitors, etc..



The reason I ask is, I heard that this doesn't really matter on Switching power supplies, but it does matter on Linear power supplies..

And Since I've never used linear for anything before.. I'm not certain what behavior they're refering to.
Title: Re: EEngineers halp Please, Power Supply question (non PC)
Post by: heedpantsnow on Tue, 13 September 2016, 18:12:56
I run 12v power supplies inside my espresso machines for lights, extra temp monitoring, etc.  Most computer peripherals (other than USB) use 12v, and obviously automotive stuff.  Arduino doo dads are often 5v.  24v for industrial logic and controllers.  PLC's and PID's commonly come in 12v and 24v flavors.  Hope that helps.

Sup heedpants



I need ~500 watts for now,  (maybe more later down the road)

Now,  would there be a difference between the 1000watt coil vs a 600watt coil  in supplying 500 watts?

The rectifier on both supplies I believe is the same, with identical chip'n'capacitors, etc..



The reason I ask is, I heard that this doesn't really matter on Switching power supplies, but it does matter on Linear power supplies..

And Since I've never used linear for anything before.. I'm not certain what behavior they're refering to.


So is this for that electric chair project you were talking about? :D

If you're drawing 500W, it doesn't matter what the spec wattage of the supply is, if you're talking about nominal wattage, as long as it is higher.  600, 1000, 5000, all will supply 500W on a 500W load.

If you're talking about maximum wattage, be careful.  It must not be exceeded, even for an instant.  So if the rating is 600W maximum, I would steer clear and go with the 1000.

Does all of that make sense?  I have a bad headache right now so it might not.
Title: Re: EEngineers halp Please, Power Supply question (non PC)
Post by: tp4tissue on Tue, 13 September 2016, 18:20:56
I run 12v power supplies inside my espresso machines for lights, extra temp monitoring, etc.  Most computer peripherals (other than USB) use 12v, and obviously automotive stuff.  Arduino doo dads are often 5v.  24v for industrial logic and controllers.  PLC's and PID's commonly come in 12v and 24v flavors.  Hope that helps.

Sup heedpants



I need ~500 watts for now,  (maybe more later down the road)

Now,  would there be a difference between the 1000watt coil vs a 600watt coil  in supplying 500 watts?

The rectifier on both supplies I believe is the same, with identical chip'n'capacitors, etc..



The reason I ask is, I heard that this doesn't really matter on Switching power supplies, but it does matter on Linear power supplies..

And Since I've never used linear for anything before.. I'm not certain what behavior they're refering to.


So is this for that electric chair project you were talking about? :D

If you're drawing 500W, it doesn't matter what the spec wattage of the supply is, if you're talking about nominal wattage, as long as it is higher.  600, 1000, 5000, all will supply 500W on a 500W load.

If you're talking about maximum wattage, be careful.  It must not be exceeded, even for an instant.  So if the rating is 600W maximum, I would steer clear and go with the 1000.

Does all of that make sense?  I have a bad headache right now so it might not.

Hrrrrrmmm....

Ok. I am going for the 1000 then.
Title: Re: EEngineers halp Please, Power Supply question (non PC)
Post by: tp4tissue on Tue, 13 September 2016, 19:11:56
OK, ordered...

1000VA coil, $113.50
50Vdc Rectifier module with 20,000muf + 5Vdc Regulator, $49.80

Total Price: $163.3 for 1000watts


Pretty solid deal..
Title: Re: EEngineers halp Please, Power Supply question (non PC)
Post by: xtrafrood on Tue, 13 September 2016, 19:46:25
Building a Colonel for your robot army? If I bring you ramen can I be spared?
Title: Re: EEngineers halp Please, Power Supply question (non PC)
Post by: tp4tissue on Tue, 13 September 2016, 19:52:02
Building a Colonel for your robot army? If I bring you ramen can I be spared?

Why does everyone assume Tp4 is Evil..

Perhaps Tp4 is good ? (http://emoticoner.com/files/emoticons/onion-head/ahaaah-onion-head-emoticon.gif?1292862489)
Title: Re: EEngineers halp Please, Power Supply question (non PC)
Post by: tp4tissue on Sat, 24 September 2016, 00:34:34
Ok, guys.. spec sheet says the relay coil is rated for 48vdc, capable of 110% of max..

My transformer should be doing 36.6v ac into *sqr(2).... 51.76v  dc

Now......  that's 107.8%

Is this ok ?

I'm thinking it's a relay, and doesn't really pull much current, rated 40ma@48v,

shouldn't xplode right ?
Title: Re: EEngineers halp Please, Power Supply question (non PC)
Post by: tp4tissue on Sat, 24 September 2016, 11:52:05
//Halp   (http://emoticoner.com/files/emoticons/onion-head/hot1-onion-head-emoticon.gif?1292862509)
Title: Re: EEngineers halp Please, Power Supply question (non PC)
Post by: xtrafrood on Sat, 24 September 2016, 12:56:40
Well above my pay grade. Sorry tp
Title: Re: EEngineers halp Please, Power Supply question (non PC)
Post by: tp4tissue on Sat, 24 September 2016, 14:03:38
Well above my pay grade. Sorry tp

(http://emoticoner.com/files/emoticons/onion-head/crying1-onion-head-emoticon.gif?1292862497)
Title: Re: EEngineers halp Please, Power Supply question (non PC)
Post by: Spopepro on Sat, 24 September 2016, 16:30:40
Ok, guys.. spec sheet says the relay coil is rated for 48vdc, capable of 110% of max..

My transformer should be doing 36.6v ac into *sqr(2).... 51.76v  dc

Now......  that's 107.8%

Is this ok ?

I'm thinking it's a relay, and doesn't really pull much current, rated 40ma@48v,

shouldn't xplode right ?

You risk a shorter life span for the part, but it should be workable.

You need to be very careful if your device has a linear power supply, as mains over voltage could really cause issues when you're already pushing the parts rating. This happened to me once, I didn't realize my home mains was 127v so my linear supply ended up close to 700v... and all my wiring was rated to 600v. Had to pull a bunch of it out and swap it with 1000v ptfe hookup wire.

Disclaimer: I'm not an EE.
Title: Re: EEngineers halp Please, Power Supply question (non PC)
Post by: tp4tissue on Sat, 24 September 2016, 21:33:29
Ok, guys.. spec sheet says the relay coil is rated for 48vdc, capable of 110% of max..

My transformer should be doing 36.6v ac into *sqr(2).... 51.76v  dc

Now......  that's 107.8%

Is this ok ?

I'm thinking it's a relay, and doesn't really pull much current, rated 40ma@48v,

shouldn't xplode right ?

You risk a shorter life span for the part, but it should be workable.

You need to be very careful if your device has a linear power supply, as mains over voltage could really cause issues when you're already pushing the parts rating. This happened to me once, I didn't realize my home mains was 127v so my linear supply ended up close to 700v... and all my wiring was rated to 600v. Had to pull a bunch of it out and swap it with 1000v ptfe hookup wire.

Disclaimer: I'm not an EE.



This may eventually relay up to 3kw,  so I did get the 12awg wires..

I wanted to get the 60amp rated relay for safety,  But alas, Tp4 can't afford it.. (http://emoticoner.com/files/emoticons/onion-head/depressed1-onion-head-emoticon.gif?1292862499)