09-11-2012, 02:37 PM
That's a shame, Al - we go down some very interesting tangents as a rule.
The datasheet I've got quotes the maximum supply voltage as either ±18V or ±22V, depending on the version. I'd been planning on some sort of dropper as there's now plenty of head-room but the clue as to value is appreciated.
I'll trust you on the 10µF cap; there's already a 3600µF one across the rectifier and the wires aren't very long but it'll certainly do no harm.
I'll have fiddle with a 100kΩ resistor across the +IN and ground as well.
An ammeter is the obvious solution but I've always been OK connecting a multimeter up if I've needed to know the current and this was only to provide a simple at a glance thing - I wasn't expecting it to prove so complicated. That said, a digital meter would have needed it's own power supply and I'd odds-on have blown it up.
- Joe
The datasheet I've got quotes the maximum supply voltage as either ±18V or ±22V, depending on the version. I'd been planning on some sort of dropper as there's now plenty of head-room but the clue as to value is appreciated.
I'll trust you on the 10µF cap; there's already a 3600µF one across the rectifier and the wires aren't very long but it'll certainly do no harm.
I'll have fiddle with a 100kΩ resistor across the +IN and ground as well.
An ammeter is the obvious solution but I've always been OK connecting a multimeter up if I've needed to know the current and this was only to provide a simple at a glance thing - I wasn't expecting it to prove so complicated. That said, a digital meter would have needed it's own power supply and I'd odds-on have blown it up.
- Joe
