L
Lance
Guest
I have a need for a quicky ą 12VDC power supply, about 100 mA max
current. I'll be using this supply as inputs to 7805 and 7905
regulators. In turn, the resultant ą5VDC is used to power an instrument
amplifier (AMP04 or AN623) and wheatstone bridge circuit.
I believe if I used two batteries I could connect the + terminal of one
battery to the - terminal of the other. These connected terminals become
my "common". The remaining terminals become my + and - source.
Can I do the same with two wall warts?
Can I connect the common to ground without catastrophe?
What's driving my questions is that we're a bunch of Civil and Mech
Engineers who don't know anything about this stuff. Currently we buy
instrument amplifiers from $300 to $1500 apiece that are very very nice,
but do 10x's what we really need. I've copied and modified some circuits
I found and built one myself that does exactly what we need for around
$25-$50 (not including our labor for assembly). It works great and I'm
proud of myself.
The downside is that my design requires a ą supply. ą supplies certainly
are not hard to find, but I'd like to use little wall warts at Newark
for $5 each that look like they could work (eg, p/n 95B0540).
Thanks for any comments or suggestions,
Lance
*****
current. I'll be using this supply as inputs to 7805 and 7905
regulators. In turn, the resultant ą5VDC is used to power an instrument
amplifier (AMP04 or AN623) and wheatstone bridge circuit.
I believe if I used two batteries I could connect the + terminal of one
battery to the - terminal of the other. These connected terminals become
my "common". The remaining terminals become my + and - source.
Can I do the same with two wall warts?
Can I connect the common to ground without catastrophe?
What's driving my questions is that we're a bunch of Civil and Mech
Engineers who don't know anything about this stuff. Currently we buy
instrument amplifiers from $300 to $1500 apiece that are very very nice,
but do 10x's what we really need. I've copied and modified some circuits
I found and built one myself that does exactly what we need for around
$25-$50 (not including our labor for assembly). It works great and I'm
proud of myself.
The downside is that my design requires a ą supply. ą supplies certainly
are not hard to find, but I'd like to use little wall warts at Newark
for $5 each that look like they could work (eg, p/n 95B0540).
Thanks for any comments or suggestions,
Lance
*****