Model Boat Mayhem - Forum

Technical, Techniques, Hints, and Tips => The "Black Arts!" ( Electrics & Electronics ) => Topic started by: More Coffee on January 21, 2012, 09:30:43 PM

Title: DIY Power Supply
Post by: More Coffee on January 21, 2012, 09:30:43 PM
good enough to fidle around the bench with .

25V/5amp supply.
The circuit:
http://electronics-diy.com/schematics/1090/laboratory-power-supply-circuit.png

My Frankenstien.

(http://www.electro-tech-online.com/attachments/electronic-projects-design-ideas-reviews/60387d1327176566-another-power-supply-q-thread-sorry-pc210236.jpg)

(http://www.electro-tech-online.com/attachments/electronic-projects-design-ideas-reviews/60381d1327176409-another-power-supply-q-thread-sorry-pc210229.jpg)

(http://www.electro-tech-online.com/attachments/electronic-projects-design-ideas-reviews/60385d1327176490-another-power-supply-q-thread-sorry-pc210232.jpg)

(http://www.electro-tech-online.com/attachments/electronic-projects-design-ideas-reviews/60384d1327176490-another-power-supply-q-thread-sorry-pc210231.jpg)

(http://www.electro-tech-online.com/attachments/electronic-projects-design-ideas-reviews/60383d1327176490-another-power-supply-q-thread-sorry-pb110220.jpg)

(http://www.electro-tech-online.com/attachments/electronic-projects-design-ideas-reviews/60382d1327176409-another-power-supply-q-thread-sorry-pc210230.jpg)

(http://www.electro-tech-online.com/attachments/electronic-projects-design-ideas-reviews/60381d1327176409-another-power-supply-q-thread-sorry-pc210229.jpg)

The case started out as an AKAI stereo tuner,no amp or anything just a AM/FM receiver.I gutted it.
 I chopped out the face plate ,then cut a strip of sheet metal from an old VCR case,laid out my front bezel, cut and drilled ,then mounted the sheet on the Chassis plate with No More Nail's mounting tape,noticeably better than the 3 Stuff,
 
The transformer came from some audio gear,fused and switched using a 15amp,125 volt toggle switch from an old roof top A/C.
 The mains current enters via an old computer monitor Mains plug in and its associated chord.
 
The heat sink is from a wine cooler, The fan/and fan controller cam from a computer power supply
 The transformer out AC filter is bits from a computer power supply,the heat sink from a television the 8amp rectifier from a back up power supply.
 
I purchased the Tip3055's,7 seg displays ,Pot's and knobs. all other discrete components and hardware are salvage.
 
I built the Volt and AmMeter based on the ICL7107's,I built these units each with their own regulator on board so there would be no messing with regulators or such when they get installed. Any DC current from 7-37 volt would do.
 
This is about as environmentally friendly as I could get.
Any questions.....Ask.
Title: Re: DIY Power Supply
Post by: john s 2 on January 21, 2012, 11:12:02 PM
Im unable to see your pictures for some reason. John.
Title: Re: DIY Power Supply
Post by: DickyD on January 21, 2012, 11:19:48 PM
No, definitely no pictures (http://i124.photobucket.com/albums/p8/DickyD_photos/Smileys/thinking1.gif)
Title: Re: DIY Power Supply
Post by: RaaArtyGunner on January 21, 2012, 11:21:44 PM

Yep no pics here in OZ   <:( <:(
Title: Re: DIY Power Supply
Post by: CF-FZG on January 21, 2012, 11:25:49 PM
The pics are located on a protected website :((
Title: Re: DIY Power Supply
Post by: Martin [Admin] on January 22, 2012, 12:31:43 AM

(http://s15.postimage.org/itqeax37b/laboratory_power_supply_circuit.jpg) (http://postimage.org/image/itqeax37b/)
Title: Re: DIY Power Supply
Post by: More Coffee on January 22, 2012, 12:47:03 AM
they may be taking a while to download, I can see them..but then im a member.
Trying to upload pic's here gets me booted everytime.

I'll try to resize them to work here.

It worked,,hope you guys/gals can see then now

its an ideal circuit that works right of the schematic,rare in most online schmatics.



Title: Re: DIY Power Supply
Post by: More Coffee on January 22, 2012, 02:11:55 AM
Hi

Its a variable voltage (0-25 volt),variable current (0-5 amp)power supply

It features current limiting,and current cut.

Which means ,If your powering up a circuit for the first time, you can set the voltage.  power on and adjust the current to where it suppose to be to power your circuit.
This is the advantage of current limiting. the circuit will draw no more that what it supposed to in theory, when there's a fault or bad connection the new circuit can rapidly acquire current,this can result in burnt wire's and damaged components from current spikes or short circuit.

If the circuit has a short..the power supply will immediately cut the current until it is cleared,

Also ,it can charge your battery packs ,because one can now set the right voltage for a battery pack,and set the current to charge the pack over night. any battery from 0 volt to 25 volt can be charged.. (not sure about Li-on or Li-poly)Its not automatic..the battery pack just cant be left alone for more than 24hr's depend on its Ah rating ..Ive charged all my 9.6 volt packs at 11 volt using 80 milliamp of current. in about 8 hrs.
with the current cut,if the battery has a problem while its charging the circuit will just cut current to the pack.be it if the pack shorts out,or a bad cell trying to acquire more current.

A power supply can also do away with needed a constant supply of batteries when trying to diagnose an electrics problem. Just set the voltage and current and as long as the lights are on ..a guy can have a limitless , continuous supply of current to work away with.

It can also give a guy an idea of how much current an entire system is going to require,this can be handy in a new build as it makes choosing an appropriate battery or pack to run the boat. and give a guy a ballpark idea of run time based on your battery amp hour rating.

And when installing a new motor and aligning the shafts,with the voltage set to the motor requirement ..slight adjustment of the motor will result in an increase or decrease in current used by the motor ,lesser current means the motor is very well aligned.

A power supply has its place. testing ,building or tuning a system before it hits the water..can save some headache's in poor performance, or operation

It gives a guy options and insight when setting up a system for the first time ,or retrofitting an old system
Title: Re: DIY Power Supply
Post by: RaaArtyGunner on January 22, 2012, 06:09:47 AM
they may be taking a while to download, I can see them..but then im a member.
Trying to upload pic's here gets me booted everytime.

I'll try to resize them to work here.

It worked,,hope you guys/gals can see then now

its an ideal circuit that works right of the schematic,rare in most online schmatics.





Photos have arrived here in OZ (Australia)  :-)) :-)) :-))
Title: Re: DIY Power Supply
Post by: barryfoote on January 22, 2012, 08:16:16 AM
They have arrived in Spain too, but I wish they hadn't. Not a clue what it is all about or what it would be used for. Reading the explanation is like reading Chinese to me!!!Makes me feel really dumb! %% %% %%
Title: Re: DIY Power Supply
Post by: DickyD on January 22, 2012, 08:42:59 AM
Sorry dont get it.

How have I managed without one all these years. (http://i124.photobucket.com/albums/p8/DickyD_photos/Smileys/thinking1.gif)
Title: Re: DIY Power Supply
Post by: derekwarner on January 22, 2012, 11:00:51 AM
don't worry More Coffee   :o....some people just chose not to understand........ >>:-(

I do see your electronic GIZMO as essentially the same as a test boiler on the stove......adjustable steam pressure and variable flow  O0...& complete with a relief valve

The purpose of this would be to trial & test a steam engine....or even run-in a steam engine  {-)

After all steam molecules & electrons are very close cousins in their behaviour  :-))  :kiss: .....Derek
Title: Re: DIY Power Supply
Post by: chingdevil on January 22, 2012, 11:32:41 AM
This looks a good thing to have, one question though, what does the sense socket do?

Brian
Title: Re: DIY Power Supply
Post by: CF-FZG on January 22, 2012, 11:41:15 AM
Any questions.....Ask.

Is there a 10-15A version of this?


Mark
Title: Re: DIY Power Supply
Post by: Circlip on January 22, 2012, 11:42:56 AM
Nice solution More Coffee, ideal for connecting to a styreene chopper.

  Sense is usually to ensure that the voltage at the far end of the wires (the ones connected to the driven unit, motor etc.) is what it says on the display. Size and length of connecting wires can give a voltage drop, sensing allows you to reset output voltage.

  Two wires from socket to driven unit, need to be same polarity connection.

  Regards  Ian.
Title: Re: DIY Power Supply
Post by: More Coffee on January 22, 2012, 04:26:31 PM
Thanks guy's.
Its just a handy gadget to have.


CF-FZG = Yes it could get reworked to 10-15 amp.. , a much larger transformer current wise.. possibly a DIY tuned microwave transformer(Cheap or free),
The rest of the components in the schematic would have to be up graded in wattage ,heavier heat sinks, wire, It would be a heavy unit..

derek warner decoy = yes ..a lot of people go their whole lives not knowing the Electrical system's and Hydraulics the theory and principal are almost parallel.. Ohm's Law Bernoulli's Principal. flow and current,  the same

And guys ..if you have ever put a string of leds together,or turned something on and got smoke or something going pop..this can eliminate that..

I posted this because for those who wish they could work on different systems without constantly getting or charging batteries...this has its place on a work bench for those so inclined..This thread is just to let those who wish to build it that the Schematic is sound..It works..
Trust me alot of schematic's out thier are flawed in some way or another.


"Unless you have built it yourself it really isnt yours"
Tim the Toolman Taylor


Title: Re: DIY Power Supply
Post by: ACTion on January 22, 2012, 08:23:33 PM
I have one each these on my bench, for various different jobs:
http://www.maplin.co.uk/bench-power-supply-with-lcd-screen-219129 (http://www.maplin.co.uk/bench-power-supply-with-lcd-screen-219129)
http://www.maplin.co.uk/dc-3-12v-3a-compact-bench-power-supply-96963 (http://www.maplin.co.uk/dc-3-12v-3a-compact-bench-power-supply-96963)
http://www.maplin.co.uk/3v-15v-adjustable-25-30a-max-linear-power-supply-30391 (http://www.maplin.co.uk/3v-15v-adjustable-25-30a-max-linear-power-supply-30391)
The little 3A one is used most often, generally to power test rigs for ESCs. The current-limiting one is used when I need an accurate digital readout of either current or voltage, and the big 2-meter lump is for heavy current applications. If you keep an eye open you'll find that Crapilns usually put one or more of them on speacial offer during the year; I dodn't pay more than half price for any of them.
DM
Title: Re: DIY Power Supply
Post by: More Coffee on January 24, 2012, 05:33:36 AM
That last one is a beast.. :-))