How to build an add-on variable voltage module for the power
|
I'd also stay with an analog regulation; analog electronics are much easier to setup (it is a very few resistors and opamps, perhaps a several caps expected) instead of a proccesor + some kind of PI regulator. I feel that at its price of $. In case you bring that within the feedback loop of your power supply, it should regulate easily. I spent somewhere around 0$ US about the venture (including the Large transformer), which isn't really poor in contrast to industrial supplies boasting identical features.
I personally needed to open it to determine what wires were what voltage. Note the BIG red/white wires. should you draw A, the floor possible shifts once the latest drops). There are also some that output PWM which may be more correct to utilize than the ADC of all cheap microcontrollers. I will explain you some thing about this ability supply.
Additionally they work as aesthetic displays. It is really a LiteOn 0W PSU with +/-V, +/-V, +V, and +V standby (underside from the PSU). Here's what it looks like on paper: Because this picture is probably tough (out of the question? If you find the regulator gets scorching use a heatsink. If you have in mind an acrylic examination bench with ample expandability, take a look at the Dragon examination bench.
For safety, an A slow-blow fuse is in sequence with the major coil from the massive mother transformer (however, there was that one accidental short that blackened my screwdriver that the fuse failed to catch... Warnings If you have previously made an ATX Electrical power Offer primarily based bench/lab offer, you've previously run the potential risks - this task is less hazardous. In the finish, on the other hand, the regulators required to dissipate additional heat than I thought, and so i threw the 2nd pcb and mounted all of the regulators on a hefty Pentium II heatsink I had scattered about.
The bases one of the TO-0 regulators used in this task are attached to different resources, so I had to find a way to isolate them. I am not a lawyer, but I hereby release myself from as much liability as I can, for just about any sort of injury you sustain, or any trouble you get into. Why five, and why 0's? The voltage panel is the prime 1. It applied 5 0 pentodes in parallel as the pass element. Also, when the ground terminal is shorted with a low-side resistor in place, the ability offer has not existing limit set.
This is how to construct an add-on variable-voltage "module" for the power provide. This venture requires the use of AC mains existing, that is more than enough to kill a human being. For the duration of make use of the regulator could get warm.
The Dragon bench supports ATX and scaled-down motherboards in addition to ATX strength supplies. It really is done with a little ATMega withA/D input to acquired the value in the energy offer and with some uncomplicated calculation it exhibit those worth. One delivers B+ switching (by switching the secondaries from the major B+ and display materials), and the other switches the .V filament power to the front panel. These two lines are then fed to regulators that are connected to the jacks about the front panel. In the finish, I mounted the xx regulators straight to the heatsink with sheet metal screws and sandwiched the LM and also the two xx's having a metal bar (that we also mounted with screws) to the heatsink, isolating all of them with some heatsink pads I discovered within the strength offer of aIBM PS/ Design 0. The LT0 opamp is split infunction, the piece An is the voltage management and also the portion B is the recent control each opamp output is linked collectively through diode so the one who output less voltage win about the 2nd, if you set your voltage to 0V as well as your present-day to An and also you short your ouput the current component will pull down his output and the voltage will drop. I also connect to this electric power supply a LCD to inform you of the set level for voltage and existing, plus the existing voltage and recent.
For a linear provide i would recommend using a foldback recent limiting scheme, primarily on something which tends to be shorted/over driven as often like a bench provide. In the finish, nevertheless, the regulators required to dissipate far more warmth than I figured, and so i threw the second pcb and mounted all of the regulators on a hefty Pentium II heatsink I had scattered about. After assembled the case is secure and usable because of the thickness of the acrylic and the pounds of the put in elements (Gravity at work).
Of course you could do that with triodes, however the optimum output voltage could be diminished. Initial you have to look for a transformer which could deal with VAC at An and something with .VAC at 00ma. Once you have developed the circuit test it meticulously and appraise the output voltage. The vinyl covering will protect the acrylic from scratches until finally it reaches the end-user. As soon as you have made the circuit test drive it meticulously and measure the output voltage. The case design and style includesbanana/screw terminals,DPDT switches, a 0K potentiometer,LEDs,male bananna plug (for that voltmeter),LED panel displays purchased in Hong Kong, andscrew/female bannana terminals for the outputs and ground. Tips I used a small piece of veroboard to build this minor addon. By housing the chances and PSU below the motherboard tray, the Dragon bench doesn't occupy very much room either.
It was based around a switching power regulator. A single matter to notice, nonetheless: V down to V is a very significant drop for the 0, and thus even when only pulling a few hundred milliamps on the +V line the heatsink gets rather toasty. It really works, also. Use a heatsink if required. On the other hand, I would like to see mm fan mounts for that HDD bay area along with a mm or larger fan mount for that PCI expansion panel to further improve cooling prospective. Use sensible wire lengths if developing a long term link with the ATX provide. Even though dealing with the Dragon bench I noted many of its weaknesses and strengths in 4 classes. I required a good electric power offer to test many of my other jobs.
You just appraise the pulse width using a timer and usually either a pin with external interrupt or a comparator input. Other than that, it is great and that i hope to use it for years to come. Warnings If you've currently constructed an ATX Electric power Supply centered bench/lab offer, you've previously operate the potential risks - this task is less hazardous. The compact feeling resistor you utilize possibly wouldn't subject much in a bench offer. If you want to offer filament energy the front panel too, you'll need windings for all those also. The simplest way to apply this is to utilize a custom made IC.
Suppose you're breadboarding a circuit that's meant to be elope a V battery? Here is the inside: I used my normal single-point terminals on PCB development. This typically makes no difference to the consumer, as the personal computer behaves exactly the same, but when you shutdown your pc, the motherboard can change from the strength offer when it's completed shutting down. Make sure you let your electric power provide discharge, absolutely unplugged in the wall plug, during their visit prior to opening up. You can find some data on it on my small Tek energy transformer page. In certain cases the can of the cap is sitting at elevated voltage (~0V) so I safeguarded them by wrapping mylar tape (the type utilized in winding transformers) close to them.
Like an undergraduate in college I based mostly my senior venture about this illustration. There will also be some that output PWM which may be much more exact to utilize compared to ADC on most cheap microcontrollers. actually. Observe that the ammeter is really displaying milliamps -- the decimal level shouldn't be there. This assumes you are doing solid-state bridge rectification as I did; if you wanna use tubes, you will need to take into account that. MyOpenPC presents a reasonable asking price to consider this dragon. It is really done with a little ATMega withA/D input to obtained the value from the energy supply and with some easy calculation it display all those value. Quality: /0 The acrylic is clean-cut and sufficiently rounded to prevent injuries.
There's nothing sacred about most of the components I used. Take away these adsRemove these adverts by Registering. possibly a fast-blow fuse would be more preferable? I in fact had to open it to see what wires have been what voltage. ) All right! Stage Background Initially, a bit of qualifications on the common ATX strength supply: Laptop power materials are Switch Mode Energy Supplies (SMPS) , which use high-frequency switching circuit components use a high-quality output voltage, with great electricity effectiveness. |
|
Author Resource:-
Should you desire you are able to meet us and discuss with us, we specialize from smaller ups device to powerful
Uninterruptible power supply
building an add-on variable voltage module for the power supply
|
By :
Venus Trister
Submitted
2011-05-09 11:35:23 |
Article From Article Mayhem
 Ezine ready view |
|
|
|
Related Articles
|
|
|
![[Valid RSS feed]](http://www.articlemayhem.com/images/icon_Rss.png "XML Feed For RSS"){kind=icon}
Category Rss Feed![[Valid RSS feed]](http://www.articlemayhem.com/images/rss.jpg "XML Feed For RSS")