The power supply of brother knitting machines can be a daunting subject when just starting out but also when you already have knitting experience and never taken care of electrical matters yourself. The following breakdown should help you decide what to do when you buy a new machine or your machine hasn´t been serviced in a while or your machine goes BANG, SIZZLE, SMOKE, STINK! (been there…)
Breakdown of power supply types in brother knitting machines
KH 900 power supply plugs directly into the hardware computer
KH 910, 920, 930, 940, 950 power supply goes through the machine on the right side where two capacitors and a resistor often need to be replaced as components age.
Kh 965 like the KH 900
KH 970 unknown
Solutions without the AYAB Hack
1.) Power supply solution for KH 900, 965 if original not supplied or broken
This is easy as all you need is to get a universal power supply that has a range between 5-12V but make sure that it is positive on the inside and negative on the outside (as pictured on original plug)
2.) Power supply for KH 910, 920, 930, 940, 950
So you bought yourself a used machines or had it standing around for some time. The first thing to do if it has not been done in the year before is to exchange the capacitors & check if the resistor is still ok (the thread should be unbroken or the drop should be perfect& shiny).
Exchange Capacitors Instructions here
Problem: You have no power cable!
a) you buy an expensive original cable on ebay
b) you print yourself a basic cable holder with the right plug size for the knitting machine and use any cable with a plug on it: for advanced electricians & 3D printers…
c) you buy a power cable (2 pole) made for musical electronic pianos from companies such as Korg, Roland, Revox, Marantz etc
They look like this:
d) (not tested) you fix a new socket to the machine that fits into the original space and use the matching cable with any 2 pin socket (where the screw holes are at 40mm distance & the space is 21x15mm) etc…
e) like d) if you 3d print the side piece you can design it to fit any socket you like.
Solutions with the AYAB Hack
The power supply is always a combination of power coming from your computer and a seperate external one for the knitting machine.
The Shield +Arduino get 5V from your PC but the knitting machine needs about 1280mA at 12V otherwise the pattern transmission will be unreliable. (you will have noticed when you have forgotten to switch the knitting machine on and it wont knit a pattern…).
The KH 900 & 965 only have one way to be supplied with power but the KH 910-950 have two options.
Option a) Power supply through plug in the side of the knitting machine for Models KH 910-950 and the AYAB Hack with internal original plug with 4 pins on shield.
Option b) (only option for KH 900&965) Power supply via external universal power plug that plugs directly into the AYAB Hack. You will need a power supply of at least 1280mA at 12V and PLUS on the outside, MINUS on the inside (DIN Norm for Europe and Japan)
This is the socket you need to solder to the shield:
LUM NEB 1R you can get it from here: Reichelt
It fits onto current shield version v 1.3!! Remember + is on the outside & – on the inside!!!
There, I hope this is helpful to you, now go forth and knit!
PS: Yes, there is a KH 920 model out there, super rare and similiar to KH 910.