Search found 5 matches

by nav
Thu Jul 09, 2009 5:29 pm
Forum: General Discussion
Topic: question about 4-20ma RTD circuit in June Q&A
Replies: 1
Views: 486

question about 4-20ma RTD circuit in June Q&A

The answer to the circuit to transmit temperature readings over a 4-20ma loop ends with the comment "The green LED is just to drop the voltage because the LM358 output can't get closer to the power rail." However, in the schematic GND for the LM358 (pin 4) is connected to the anode of the green LED....
by nav
Fri Dec 05, 2008 9:48 am
Forum: General Discussion
Topic: How to use a relay in a breadboard.
Replies: 8
Views: 2300

I think it is a mistake to try to adapt everything to a solderless breadboard. Besides making an electrical connection, you also want to have mechanical stability, strain relief of cables, easy access to components, etc. I often mount a solderless breadboard on another project breadboard which gives...
by nav
Sat Nov 29, 2008 2:38 pm
Forum: General Discussion
Topic: "for use with information technology equipment only&quo
Replies: 2
Views: 670

"for use with information technology equipment only&quo

If you see that on a small switching power supply, what concern are they addressing? Does it mean it shouldn't be used with inductive loads?
by nav
Fri Oct 24, 2008 8:35 am
Forum: General Discussion
Topic: wall wart questions
Replies: 12
Views: 2147

If they are unregulated, the higher current one will have lower resistance. The rated voltage is given at rated load, so if you use it with a lower current, expect the voltage to be higher. What's a good way to understand this? Would a higher current wall-wart have less turns on the secondary and t...
by nav
Thu Oct 23, 2008 6:35 pm
Forum: General Discussion
Topic: wall wart questions
Replies: 12
Views: 2147

wall wart questions

Just a couple of questions about wall-warts: 1. Generally, is there a correlation between a (DC) wall-wart's current rating and its internal resistance? (i.e. given 6V, 300 mA and a 6V, 700mA wall-warts, which would you expect to have the greater internal resistance?) 2. Suppose you have KVM switch ...