I need to buy some diodes for 7A 24V solenoids. Can someone advice what is better and lower recovery time?
For my test i used:
BYW81-150 of ST
But it's too expensive.
Here's some cheap diodes i've found:
Schottky diodes:
MBR1545CTG 15A/45V TO-220
RHRP15120 15A 1200V TO-220-2
http://www.fairchildsemi.com/ds/RH/RHRP15120.pdf
(the cost is higher than others)
MBR1080 10A/80V TO-220
http://www.datasheetlib.com/datasheet/27229/mbr1080_on-semiconductor.html?page=2#datasheet
If the solenoid is drawing 7A, then it will try to keep 7A going when it is turned off.
So any of those look ok to me.
Yes, they are good for Ampere and voltage. But i don't know which have better quality and especially which is faster.
They come from known suppliers, so you can expect manufacturing & design quality to be similar.
2nd one, RHRP15120, looks fastest. Times down in the sub-microsecond range, 75nS.
(0.075uS)
Since you cannot turn a solenoid on at off at very high frequency, the recovery time isn't particularly relevant.
That's what i tought, but i don't know why i see projects with solenoids that always use schottky type diodes. There is a reason?
Lower voltage drop across the diode = lower heating during high current flow.
my friend, we have a saying, putting the cart before the horse.
WHY do require high speed ? what actual problem have you had that shows that 'low' speed is not working ?
if you do not know, then explain your circuit and ask how to select the parts.
Are you concerned about the back EMF from the coil of a solenoid or relay?
dave-in-nj:
Are you concerned about the back EMF from the coil of a solenoid or relay?
The diode is for this.
As i wrote before:
Yaro:
That's what i tought, but i don't know why i see projects with solenoids that always use schottky type diodes. There is a reason?