Why are (most) telecom systems supplied with -48Vdc?
30218
Why do PBX systems use -48 V?
134041
Transformerless power Supply - 24VDC, 120V AC and 230V AC
117948
Why do we use AC for long distance transmission?
61260
Why do utility companies supply at a frequency of either 50/60 Hz?
13490
High Voltage Powerlines - clarification of energy loss
19982
Is CAT5 cable good enough for RS-485 vs "true" RS-485 cable
82647
Why do some devices have 200V on the case?
69776
Why is the diode forward voltage constant?
4135
Why do many laptops run on 19 volts?
103245
Why is it safe to use 15 A receptacles on a 20 A circuit?
77276
What would happen if I choose a connector with current rating smaller than the actual current?
58904
Why too many capacitors in parallel for Vdd supply net? Can't we just add all to replace with one big capacitor?
91243
What are the highest DC and AC voltages or currents that can be considered as safe?
41616
Why are all of my appliances becoming energized when ground wire is excluded?
69578
Is it really possible to "boost" 6 V DC to above 50 kV? Or even 400 kV?
126465
How does DC transmission require several times less wire than AC?
16248
How much voltage/current is "dangerous"?