Optocoupler & MOSFET for ~75W heater at 12VDC
hello , taking time possibly me.
i need build device switch 75w of 12 vdc power arduino. want switching isolated arduino. after research came across posting.
http://electronics.stackexchange.com/questions/17116/how-to-drive-a-mosfet-with-an-optocoupler
i planning on turning electric heater on/off. keep option open pwm may not necessary (more nice have). power source 12v battery (so max of ~14.8vdc). heater rated ~70w. when in use, heater remain on hours.
the parts planning on using are:
ic1 - pc817 optocoupler
t1 - irl40b209 n-channel mosfet
d1 - rl204
d2 - 1n524 zener
r1 - 330 ohm
r2/r3 - 2k2 ohm
cheaper parts may available more interested in availability , having works saving money.
if possible, may want use pwm on pin 3, default frequency of 500hz.
i adapted schematic above internet link. have attached jpg file post.
the diodes not needed heater have decided include them circuit compatible other things. if ever right, don't want have start on again.
the irl40b209 has rds on of 1.25mΩ. if assume power switching of less 100 watts , voltages between 10 , 15 volts, calculations correct have less quarter watt of heat dissipate? if true, heat sink use anyway isn't necessary. (10a * 10a * 1.25mΩ = 0.125w ?)
so, questions are: circuit viable described switching? should possible use pwm @ 500hz?
i need build device switch 75w of 12 vdc power arduino. want switching isolated arduino. after research came across posting.
http://electronics.stackexchange.com/questions/17116/how-to-drive-a-mosfet-with-an-optocoupler
i planning on turning electric heater on/off. keep option open pwm may not necessary (more nice have). power source 12v battery (so max of ~14.8vdc). heater rated ~70w. when in use, heater remain on hours.
the parts planning on using are:
ic1 - pc817 optocoupler
t1 - irl40b209 n-channel mosfet
d1 - rl204
d2 - 1n524 zener
r1 - 330 ohm
r2/r3 - 2k2 ohm
cheaper parts may available more interested in availability , having works saving money.
if possible, may want use pwm on pin 3, default frequency of 500hz.
i adapted schematic above internet link. have attached jpg file post.
the diodes not needed heater have decided include them circuit compatible other things. if ever right, don't want have start on again.
the irl40b209 has rds on of 1.25mΩ. if assume power switching of less 100 watts , voltages between 10 , 15 volts, calculations correct have less quarter watt of heat dissipate? if true, heat sink use anyway isn't necessary. (10a * 10a * 1.25mΩ = 0.125w ?)
so, questions are: circuit viable described switching? should possible use pwm @ 500hz?
looks reasonable, , yes don't need d1 resistive load, inductive load motor or relay.
i make current 6a, , power dissipation < 0.1w
with pwm you'll have checkout switching speed, switching losses may come dominate.
if can cured adding mosfet driver drive mosfet gate several orders of
magnitude faster.
you drive mosfet gate more 10v if want.
i make current 6a, , power dissipation < 0.1w
with pwm you'll have checkout switching speed, switching losses may come dominate.
if can cured adding mosfet driver drive mosfet gate several orders of
magnitude faster.
you drive mosfet gate more 10v if want.
Arduino Forum > Using Arduino > Motors, Mechanics, and Power (Moderator: fabioc84) > Optocoupler & MOSFET for ~75W heater at 12VDC
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