Introduction

This description refers to the Issue 20 and later NCC series controllers.
Circuit Diagram, issue 24

Components Used

Notes

1. 48v version requires a transistor capable of dissipating 1.8 watts.
2. Numbers not used are present to preserve same numbering between Pro and NCC.
3. 2N5550 is used on 48v controllers: C an E are reversed w.r.t. BC series.
4. MPSA06 is used on 48v controllers: C an E are reversed w.r.t. BC series.

9v1 supply decoupling

Capacitors

C1	1µ0	Input decouping	May be removed
C2	100n	Input buffer stability
C3	4µ7	Ramp capacitor	May be reduced
C4	470p	PWM oscillator timing
C5	150p	Current source stability
C6	4µ7	Ignition auto-off timing
C7	10p	Hiside current limit
C8	100n	Ignition pump
C9	2200µ	Main capacitors	two off
C10	1µ0	Hiside gate supply
C11	470p	Half bridge timing
C12	10p	Current limit timing
C13	1µ0	Curent sense ref decoupling
C14	1µ0	Current limit stability	May be reduced as low as 20n
C15	1µ0	Direction line decoupling
C16	1µ0	Ramp clamp decoupling
C17	47µ
C18	1µ0	Reverse input decoupling
C19	1µ0	Parking brake timing	May be altered
C20	1µ0	Demand zero decoupling	May be removed
C21	10n	Direction latch stability
C22	10n	Direction latch stability
C23	10n	Motor noise supressor

Notes

1. Capacitors marked as 'may be reduced' or 'may be removed' are do do with response speed.
   See Pro Series: ramps

Other relevant pages

• Circuit Diagram NCC Issue 24
• How PWM works
• Pulse width modulators
• MOSFET current sensing
• Testing drivers and output

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