TP600 - TPU PULSER

[z_p_e]

PULSE WIDTH QUESTION

@All,

What range of pulse widths would folks here like to have?

Here are some examples:

1) 100ns ~ 500ns in 100ns increments
2) 50ns ~ 250ns in 50ns increments
3) 20ns ~ 100ns in 20ns increments
4) 2ns ~ 510ns in 2ns increments (deluxe $$ implementation)

Perhaps longer than 500ns? 

Thanks,
Darren

[z_p_e]

In reality guys,

We have limiting factors to consider.

The power MOSFET takes minimum 50ns from 10 ~ 90% to turn on, and about the same to turn off. Therefore to leave some margin and also give the coils some time to energize, I would suggest that the shortest pulse width be about 500ns. Does this make sense or am I off track here?

I really doubt SM went beyond 1 MHz with his frequencies, and so I propose that the longest pulse width be 1us, which will limit the operating frequency to 1 MHz.

One RANGE position can be eliminated, and so a 6-position rotary used instead of a 12-position.

Any thoughts?

Darren

[Dingus Mungus]

Either way I would still want to build one, but I will say since this driver could be mulit use in our kind of research, that perhaps keeping as much of the upper range as possible would be worth while still. I'm mainly saying this because you can typically buy 10hz-10mhz pulse gen on ebay for 30-50 bucks.

Thanks for designing these great units! I'll be building the 900 model soon!

~Dingus Mungus

[otto]

Hello all,

as we know the highest frequency for a 15" TPU is 245kHz maybe its enough that the pulser can reach 500 - 1MHz.

@Darren

veeeery nice job done. Im waiting for the 900 design and then I will build it.

Otto

[turbo]

hi Daren,

considering the lightning band app.246khz they have to be as fast/short as possible.
lightning itself does not last seconds, it's there and then its gone.
with transistors and the rlc comes the dirty harmonics.
this does not happen when using crystals.

"sorry, theze are not piezo stacks, however they look like it"

that could point out to perfect frequency using quartz, so pherhaps we can do an add on for inserting crystals? (Pierce Colpitts)

However these do have responses at approximately three times this fundamental frequency, five times, seven times, etc.
Those are for example the third overtone(5000Hz), fifth overtone(35000Hz), seventh overtone(254000Hz), etc.

Marco.