Question

You are using 24V DC for your hobby 3D printer. The resistance of your heated bed is 150 Ohms. What current does it take to apply full power? If you use a relay to power the heater and use 120V AC instead of DC, what resistance would be heater need to be to achieve the same total power. What current does it take to apply full power?

Answer 1

Given data

DC Volatage (V_DC) = 24 V , Resistance (R) = 150 Ohms ,

AC Volatage (V_AC) = 120 V

Now For DC system,

Power (P) = (V_DC)² / R

               = 576/150

          P = 3.84 W

Current (I)

   I = P/V_DC

    = 3.84/24

I = 0.16 amp

Now Using AC power supply,

Resistance (R)

R = (V_AC)² /P

   = 14400/3.84

R = 3750 Ohm

Current (I)

I = V_AC / R

= 120/3750

I = 0.032 amp

answered by: anonymous