Ray Haddad skriver:
No, that's what is called an unregulated power supply.
A regulated power supply contains an active omponen thet regulates the output voltage and/or current.
Klaus
Greg Procter skriver:
Klaus
On Sun, 23 Dec 2007 08:01:53 +0100, I said, "Pick a card, any card" and "Klaus D. Mikkelsen" instead replied:
They're all part, Klaus. Try building a regulated power supply without those. The wall cube forms the first part or a chain.
-- Ray
On Sun, 23 Dec 2007 17:52:33 +1100, I said, "Pick a card, any card" and Eddie Oliver instead replied:
No. I won't. It's basic power supply design. Look it up.
On 12/22/2007 11:18 PM Ray Haddad spake thus:
What a lame-ass answer.
But I see what you've been doing: playing with semantics, all to avoid owning up to your being totally wrong in your arguments so far.
Yes, a wall wart can form PART of a REGULATED power supply, IF the regulating part of the circuit is inside the thing being powered. But BY ITSELF, the wall wart is (always, in my experience), UNREGULATED. To put it more precisely, any power supply that only contains a transformer, rectifier and filter is UNREGULATED by itself. Anyone reading my many previous posts (except, apparently, you) would have gotten that by now.
And yes, we know (or at least I do) that zener diodes are used as voltage regulators. But as I said, I've never even seen a zener in the many wall warts I've dismantled, meaning that they're totally unregulated.
On Sun, 23 Dec 2007 00:06:37 -0800, I said, "Pick a card, any card" and David Nebenzahl instead replied:
Actually, I never, ever stated that ALL wall warts contained regulated power supplies. That was down to you and Greg. You claimed you opened billions of them and never found even one. Ok. Not billions but you see what you did, right? You moved my statement over to where YOU could win. Instead of sticking to the original comments I made, you moved it over and made a big stink over it.
In fact, I never stated that ALL wall warts contained regulated power supplies only that they made up a composite power supply with their load. Go back and see. Loading is necessary to get them to be at the proper voltage according to what is printed on them. For you to make such a stink over your own misleading comments is very bad form, David. Very bad.
David, I spent over 40 years in electronics. Don't pretend to tell me what a regulated power supply consists of.
Thank you. I have seen them there. You can't have opened every wall wart in existence. However, let me point out that you probably opened those you believed weren't working properly. That leads me to believe you opened them because the voltage was incorrect. That also leads me to suspect that because of your mistaken beliefs, they weren't really bad at all just unregulated.
I had a friend who put a 7805 circuit on a 12 volt wall wart. It promptly caught fire. Both the circuit he built and the wall wart. The reason? There was a 7512 in the wall wart. Disaster.
This entire subject has been hijacked by you and Greg. All I stated was that there were no 13.8 volt batteries out there and that the wall cubes that put out that voltage were chargers, not power supplies. Now, kindly knock it off and stick to what you know.
-- Ray
Must resist temptation . . . even if it exceeds my capacity
I may well be an idiot, (I'm answering you afterall) but why is it the "laboratory (style) power supplies" I can buy from electronics chains like Dick Smith and Jaycar are 13.8 volts???
Any automotive battery charger that put out a peak voltage of 13.8 volts would take until eternity to charge a 12 volt car battery to full charge. (assuming a perfect battery with no internal losses or resistance)
Regards, Greg.P.
You give credit for ignorance? - are you a credit card company by any chance? ;-)
Ray, a 12 volt lead-acid battery will charge to 13.8 volts and retain that voltage for a period of time. One can draw sufficient current from said battery to run a average model railway locomotive without the voltage dropping noticably. If one uses a small trickle charger with a car battery to provide power for a layout (common 1930s-1960s) then one's layout will be operated at
13.8 volts smooth DC.Regards, Greg.P.
A diode for rectification, followed by a series resistor, followed by a zener diode to ground, paralleled with a smoothing capacitor constituted a voltage regulator way back. It's not exactly a high current supply though.
Regards, Greg.P.
Quote from first reference: "Control voltage: constant voltage 14.5V to 14.9V (per 12V cell 25 degrees Celsius) Float: control voltage: 13.6 to 13.8V (per 12V cell 25 degrees Celsius)"
If one charges a battery to 13.8 volts it will be at 13.8 volts.
By that reasoning my key-chain LED torch (flashlite) is a mainframe computer controlling a CIA intelligence gathering network!
Here's a laboratory power supply from Jaycar Electronics:
Here's a laboratory power supply from Dick Smith Electronics:
Sorry the links are so long but that takes you to the specific product.
I've been involved with fitting ship, boat and truck radio/depth finding etc gear (AWA NZ, a division of RCA USA) All our gear was rated at 13.8 volts because that's the operating voltage found on batteries in circuit in those situations.
On Mon, 24 Dec 2007 08:34:58 +1300, I said, "Pick a card, any card" and Greg Procter instead replied:
That's because they run from a generator or an alternator and not a
12 volt battery which is never, ever going to be at 13.8 volts.-- Ray
On Mon, 24 Dec 2007 08:11:37 +1300, I said, "Pick a card, any card" and Greg Procter instead replied:
It's still one.
-- Ray
On Mon, 24 Dec 2007 08:01:08 +1300, I said, "Pick a card, any card" and Greg Procter instead replied:
Oh, yeah! No credit limits either. No application fees. Post your PIN here and I'll show you.
-- Ray
On Mon, 24 Dec 2007 07:59:52 +1300, I said, "Pick a card, any card" and Greg Procter instead replied:
Because the circuits those things run on are powered by an alternator running at 13.8 volts. The battery in most vehicles is only for starting the vehicle and for running things for a short time when the engine is stopped.
I'd love to read your theory behind this one, Greg. Remember, a 12 volt battery is not a 13.8 volt device. It's a 12 volt device.
-- Ray
On Mon, 24 Dec 2007 08:06:14 +1300, I said, "Pick a card, any card" and Greg Procter instead replied:
No. It won't.
-- Ray
On Mon, 24 Dec 2007 08:18:11 +1300, I said, "Pick a card, any card" and Greg Procter instead replied:
Never.
-- Ray
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