While we are on the subject...could someone post a good page that talks about fuses or comment on their use in our homebrew systems? I have never used them (go figure) and would like to add them to decrease the possibility that I have another fire...armen, I said decrease
D
'fuses are like insurance. you'll never know it's there until you really need it".
just a few helpful comments about fuses that i've learned from experience.
1. use the LOWEST value fuse as you can without blowing it.
2. fuses go in series on the positive terminal in a DC system closest to the power supply, as some already stated.
3. isolate the fuse so there aren't any other electronic devices that can affect it.
here's a crude sketch for ya:
-----------> FUSE >------------------------------
| |
+ |
_|__ DAT/Pre/ADC
__ |
| |
|----------------------------------------------------|
in determining what size fuse to use, i would consult your manual FIRST to look for "Current Draw", "Current Comsumption" or "Power Consumption".
if you have a "Power Consumption" value, divide that by your operating voltage to obtain "Current Comsumption". remember Power (Watts) = Voltage (V) X Current (Amperes).
if you have multiple equipment, add the individual current draw to obtain your total Current draw. mind you, basically all of the electronic equipment we use only draw a very small amount of current and is usually expressed in mA (milliamps).
DO NOT use AmpHour ratings to determine current draw. AH is a number that has a time value factor into it. i've seen some people determine their current draw by using their battery's "AH" rating and that's totally wrong. you're looking for an instantaneous current draw from a battery and NOT over a certain period of time.
hope this helps and please see my example below:
marc
==========================
example:
Beyerdynamics MV-100 pre
Current Draw: 85mA per manual
Voltage (DC plug): 24V per manual
i'm using 2-12V 7.5AH batteries in series to power my MV-100.
fuse size used: 100mA (.1A)
i'm 100% positive that a 1A fuse will work just fine, but that's almost 12X the current rating. it's almost like there is no protection at all by using a 1A fuse.