Minipulse Rev D first attempt

[Impulse]

Hi guys I have just ordered a minipulse kit from silverdog I have tried the barracuda pi but I have had so many issues with it I thought I would give the minipulse a go as it is better documented (which is better for me as a beginner) I have the step by step guide to go by and I will post my findings at each step and I will follow to the letter what to do. I hope this will go a bit better than the barracuda (I will continue to try and learn from it). If I get stuck I hope you will be willing to help another beginner, sorry in advance for my ignorance when it comes to electronics.

[Impulse]

still waiting on delivery (paypal went spaz and held the payment for 8days!)

[Impulse]

The kit has landed! i have only had a few moments so far and i have done stages 1 (-4.979v) and 2 (5.084v) i will post pictures later. For stage 3 i started to sort the components and i cant find C20? i have looked at other posts to see what type i am looking for and it looks like it is one of the ceramic types it calls for a 100pF so i used my multimeter on both and neither are 100pF, any ideas? The last thing i want to do is put a component in the wrong place!

[silverdog]

you should have C20 a 100pf and C8 220pf - do either have any markings on them ?

[Impulse]

Heres a pic, one says 221 sunion and the other is a 101 sunion, i think it might be my multimeter as it reads all of the others fine appart from these two so i will use the 101 for C20 and 221 for C8?



Stage 3 here we go!

[Impulse]

OK so i have done stage 3 with success i think a question though, my batt voltage is a little on the low side (my fault) the manual says as the batt voltage drops the pulse width will increase (or get wider) but it says i should have 58us at 12v i would expect to see 58us+ as my batt voltage is low but i have 48us?

heres a scope pic



Hz - 1.046Khz correct
Pulse width 48us battery voltage is 11.4v

pic of the board

[Impulse]

does this look ok? this is CH1 TP1 and CH2 U2 pin2 the last check for STEP 3 i thought i would cover everything in every step

[Qiaozhi]

does this look ok? this is CH1 TP1 and CH2 U2 pin2 the last check for STEP 3 i thought i would cover everything in every step

[ATTACH]35656[/ATTACH]

Yes, that looks good. You can see that the voltage doubler is synchronizing with the TX oscillator.
At this stage I wouldn't be too concerned about the TX pulse width. It might just be a problem caused by the low battery voltage, or a component tolerancing issue. You can come back to that later.

[Impulse]

ok so i have managed to get stage 4 on the board but i have attached my scope to the balance resistor and i get this

here

[Impulse]

o and i have tried the headphone trick and i dont get any sound?

[Impulse]

[Impulse]

ok ignore the last 3 posts i have my head on now!! i have TX RX connected to the inner most winding and pin 3 of PL2 to the outer most winding now this is the o-scope image i get

here

and i now get the tone in the headphones yay!

[Impulse]

Hey guys does the scope image look rite I don't want to move on without confirming that it is correct?

[Qiaozhi]

Hey guys does the scope image look rite I don't want to move on without confirming that it is correct?

Your PC scope appears to be limiting the amplitude so that you're not seeing the full flyback voltage. Try changing the setting on CH1 from x1 to x10, and use a x10 probe.
However, since you can actually hear the TX oscillator in the headphones, it's most likely ok for you to carry on.

[Impulse]

My scope cannot handle more than 80v in 10x I don't want to break it . Thanks Qiaozhi for you help again