On 10 Dec 2005 15:01:16 GMT, "John B"
<spamj_baraclough@blockerzetnet.co.uk> wrote:
Quote:
On 10/12/2005 the venerable Dope mcSmoke etched in runes:
John B wrote:
On 09/12/2005 the venerable Dope mcSmoke etched in runes:
It's been a few years since I had an electronics course, so I need
help with a relatively easy question.
I need to reduce 24 volts DC to 5 volts DC. I think it's just a
matter of a couple resistors but am unsure. The amperage is
relatively low (not sure exactly).
Can anyone help? Details would be much appreciated.
Thanks,
-Dan
7805L regulator. Costs about 50 cents and comes in TO92 package.
But it might get hot fed with 24V
Yes it might, that depends on the current consumption. But it won't get
any hotter than the dropper resistor in a potential divider and the
output will more stable.
If in doubt use a standard 7805 1A regulator bolted to Mr mcSmoke's
dope tin.
|
If you're talking about more than 100 mA, consider a Simple Switcher
from National Semiconductor. Check out LM2678-5.0. It won't need
a heatsink for currents up to 2 amps or more. The website "web
bench" will design the circuit for you, including giving you a parts
list.
http://www.national.com/appinfo/power/webench/