H
Homer
- Jan 1, 1970
- 0
Hi All,
I am planning to light up 178 LEDs (3.4V-3.8V, 25MA) using a 18V/1A
Adapter (DC radio shack transformer) and I need a little help.
Power Adapter says that is 18 volt but when I test it with volt meter
it shows 22V. When I connect a string of 6 LEDs (plus small resistor)
with it voltage is dropping to 21.4 (and shows 9.4ma current)
I don't have problem calculating my resistors (I am using
http://led.linear1.org/led.wiz) but it seems my 18V (or 22V) Adapter
is not really what is says (it drops).
My question is what should I put in that web site as my Source
Voltage? (22V? 18V? or something else).
Thanks in advance,
Homer
I am planning to light up 178 LEDs (3.4V-3.8V, 25MA) using a 18V/1A
Adapter (DC radio shack transformer) and I need a little help.
Power Adapter says that is 18 volt but when I test it with volt meter
it shows 22V. When I connect a string of 6 LEDs (plus small resistor)
with it voltage is dropping to 21.4 (and shows 9.4ma current)
I don't have problem calculating my resistors (I am using
http://led.linear1.org/led.wiz) but it seems my 18V (or 22V) Adapter
is not really what is says (it drops).
My question is what should I put in that web site as my Source
Voltage? (22V? 18V? or something else).
Thanks in advance,
Homer