Parts are ordered.
When I order parts it is usually through Digikey because they are quick and easy... tho for the higher value parts I always use
OCTOPART to find the best price possible. Octopart is an AMAZING parts search engine that will scour nearly every distributor on the net and show you a large table with the best pricing available.
Here is an example with my IRLB4030
Do you see how awesome that is? We can instantly see that Future Electronics is FTW with a 10pcs minimum. :wink:
There are two tips you can take to the bank. OSH Park and Octopart.
Smallest BOM I have had since I can remember
4030 fets
Attiny uControler
22uF cap
Battery holder
I have the 90V TVS diodes, headers, bypass caps, etc.
Now while the parts are being shipped I will lay out the PCB. Before I send the PCB out for manufacturing I will print out the PCB on paper (1:1) and lay each part down to make sure my footprints are correct and that nothing is mirrored etc. PCB's are ordered from
OSH park - the only place to order prototype (or even short run) PCB's (thanks to Big Moose for turning me on to that)
I purchased enough parts to build 10 boards. After I shake out all the mistakes I will do a run of 100 boards to get prices to the rock bottom.
new subject:
I am going to drop the PWM capability and double up on the output pins. After I change the switch to an input pin that leaves 3 outputs for 2 fets. I will probably tie the fets together - so 3 output channels driving 200nC. I think I am going to be able to pull that gate up and down plenty hard - and I think the tri-states will be acceptable to drain the gate down in the case of BOD.
Perhaps I can combine the switch input with the HVC input and free up one more drive channel for the fets. I would then have to think about the behavior of the chip tho....
SWITCH INPUT:
Low means turn off
High means turn on
Toggle means clear latched condition
HVC INPUT:
Low means latch to the OFF state
High means we stay latched
A toggle of the Switch clears the latched state....
So I would have to find a way around that.
Probably best to keep two inputs open.
-methods