Note: There may be some confusion coming from the fact that the diagram from Keith Walker's article and my PCB are slightly different. He uses half of one chip (IC1a) in the integrator, and then two halves of the second 358 as an oscillator (IC2b) and the comparator (IC2a).

On my PCB the first chip takes care of the integrator _and_ the comparator, and one half of the second chip is just the oscillator. If you want to use my PCB you have to carefully identify all the components -- I didn't do it on my drawing and now it would take too much time. Sorry. EJB

Parts list for a miniature high rate speed control, designed by Keith Walker

Resistors

R1: 100 k
R2: 10 k
R3: 220 k
R4: 10 k
R5: 10 k
R6: 10 k
R7: 4.7 k
R8: 10 k
R9: 10 k
R10: 22 k
R11: 1 k
R12: 100 k
R13: 1 k
R14: 1 M
R15 (-- R17): 1 k
VR1: 25 k
VR2: 25 k

Diodes

D1: 1N4148
D2, D3: 1N4001 (1 A, 50 V)

Capacitors

C1: 0.1 uF [uF = microfarads]
C2: 2.2 uF
C3: 0.1 uF
C4: 0.1 uF
C5: 10 uF
C6: 0.01 uF, 25 V

ICs and transistors

Q1: 2N3906
Q2 (-- Q4): IRFZ40 or equivalent
IC1, IC2: LM 358