Guru
Joined: 21/06/2018
Location: AustraliaPosts: 1210
| Posted: 12:02am 10 Mar 2024 |
Well after spending quite a few hours trying to assemble a BOM (bill of materials), I wanted to include sources for some parts and pricing etc. But as some will have suitable parts to hand and they may consolidate purchases for low cost or free shipping from a few suppliers it just got harder and harder.
So, I decided to just present the raw bill of materials and not give part numbers (for generic connectors LEDs etc) and sources and prices. However for the 4 way and 6way main connectors for 48V and Fans etc I highly recommend a pluggable terminal block such as the Phoenix MSTB2.5 series - I dont recommend you actually buy them as they are fricking expensive.
There are plenty of 2nd and 3d and more sources of cheaper alternatives that are probably even plug compatible with the Phoenix types. It is a low current application but fixed PCB to wire terminals are tedious to undo and rewire with a greater chance of crossing wires (especially a year down the track) a rouge strand etc - the pluggable types make it childs play to remove and install the PCB again in a few seconds.
Of course there are also right angle sockets that could be used and various plugs with wires that are opposite the pins, others with the screws opposite the pins and the wires at right angles etc, personal preference plays a part as to what will suit you.
I also recommend that you should purchase from Ali some pre assembled 8way 6way 3way double ended rainbow coloured wire, single inline sockets each end 2.54mm (0.1") spacing, at least 200mm long for connections to controller to PowerPCB, Front panel LED and switch connections, controller to LCD etc. they are only a couple of dollars for 10 and good to have a few. The variac pot can use a double ended 3 way type. You can hard wire a 3pin connector to the pot or even cut the connector off one end and solder direct.
I will be using a 10 turn panel pot (from Ali) for my variac as you can dial in voltage to 1 decimal point then - ( still to be proven) the single turn pot is pretty coarse with ~ 1V per degree of turn.
For the controller the only parts a bit special is the 12V & 5V regulators, the opamps specified - with rail to rail input and output, The ZMPT107 2mA transformer and the BS170 mosfet, some other types (ie 2N7000) the footprint is backwards - it can be used if rotated 180 degrees from the silk screen. The PS2A regulator can be substituted for the PS2, the silkscreen has the number MP1584 which is wrong - it should say Mini360 which are cheap and from Ali. Just ensure the pot is adjusted for 5-5.1V before you power up with the Ics installed.
So hopefully today I will post the BOM here.
Edited 2024-03-10 11:05 by wiseguy