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From: Mark Lloyd
Subject: Re: 24 VAC to 9VDC supply
Date: 4 Dec 2002 22:27:09 -0600
References: <firstname.lastname@example.org> <email@example.com>
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On Thu, 05 Dec 2002 04:00:56 GMT, "Smiff"
>"Mark Lloyd" wrote in message
>> On 4 Dec 2002 02:30:38 -0000, Steve W.EE
>> >What is the quickest, dirtiest, cheapest way to get
>> >9 volts DC from a 24VAC source.
>> You won't need a transformer, but can connect the 24VAC directly to a
>> > Need about 150ma
>> >of current but the DC does not need to be regulated.
>> >Half-wave rectifying will give too much DC voltage,
>> >it would burn up a regulator since I don't have a
>> >place to heatsink one.
>> I doubt it. The power dissipated in the regulator is:
>> Where Vi is the input voltage, Vo is the output voltage, and I is
>> current. In your case.
>> (Vi-Vo)*I = (24V-5V)*.15A = 19V*.15A = 2.85W
>> Less than 3 watts isn't that much. You could even use one of the
>> low-power regulators (78L05). These handle up to 150mA, are in TO-92
>> cases, and don't use heatsinks.
>> > Some solution which involves
>> >cutting up a wall-wart making use of the parts inside
>> >would be ideal.
>> If you've got a regulated 5V wall-wart you don't mind cutting up.
>> 21 days until the winter solstice celebration
>> Mark Lloyd
>> "There's no more proof for the existence of God than there is for the
>existence of the
>> Easter Bunny. That's right. The Easter Bunny."
>That's why they call it, "Faith!"
In that case "faith" is a synonym of "stupidity". It seems to be
easier for me to see that rather obvious fact, since I escaped a lot
of the early childhood brainwashing.
21 days until the winter solstice celebration
"There's no more proof for the existence of God than there is for the existence of the
Easter Bunny. That's right. The Easter Bunny."
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