Hardware » Helios

V_GS should be -10 and must not exceed -20V;

U2=(U/(R1+R2))*R2

R1=330
R2=470
[R1|R2]=193.875
Result=28.2; 0.714282%
48V: Reference=-19.8
36V: Reference=-14.85
15V: Reference=-6.1875

U2=(36/(3300+4700))*4700

Bei -4,5 V_GS ist R_DS 0,110 Ohm; V_DS=-0,44V; 1,76W; 2W zulaessig bei T_A=70°C

[20251209 mase]:
Measure whats going on, the MOSFET broke.
V_GS 12,8V looks good. Another one broke.

[20251210 mase]:
Application note
PJW4P06A-R2
-4.0A; I_DM=-16A; 2W

Add capacitors from gates to sources.
Adding one at the N-MOSFET may make it unpredictable.

Make R2=27k
VGS=-9,729 @ 36V

• 4,285714286V @ 12V
• 12,85714286V @ 36V
• 17,14285714V @ 48V

0,15 Ohm R_DS very bad
4A × 0,15 Ohm = 0,6V
0,6V × 4A = 2,4W

Elkos:
CD1H476M6L07KVR
0.61 Ohm; ca. 60A; 300A total
Theoretisch (ChatGPT, nur ESR) braucht er 95µs. Bei 0,5A 3,4ms.

Neue MOSFETS:
SQJ465EP-T1-GE3
I_DM=-25A; 45W (15W hot)

Besser DI020P06PT-AQ?
I_DM=-70A