A closer look at the AF108 bi-polar drive circuit

[waltr]

dbanner,
Yes, simulating the timing chips is tough when trim values and timing requirements are unknown.

You could replace the timing chips with Pulsed Voltage sources in LTSPICE then play with the parameters to see what effect various timing has of the analog sections.

[Andi68]

Which transistor do you want to replace the BUY92?
I would think that before I create a layout

[dbanner]

I've come too far to turn back now. So I will continue on with making a pcb for the bipolar drive circuit and then the "ducks guts" rest of the thing. Experimentation with the timing and control is a bridge I'll have to cross when I get there.

[dbanner]

Now about the simulations. After finally figuring out simple and basic how to add third party models to LTspice, well, simulating the timing and sampling was somewhat stupid, since I can't know the values of those trimmer pots, I can only verify that the simulation works, impossible to know the precise nature of the pulses generated by the actual device( the sample delays and sample widths and tx drive pulses, etc.), now I feel somewhat like mild idiot.
Carl will have to dig out his unit and put oscilloscope to the circuit
On the upside, the timing and control module can serve as sort of universal pulse controller, as it has the possibility of adjustment of several of the critical parameters of the drive and sampling pulses.
Tinkering with the simulation clearly shows the tx1 and tx2 pulses interspersed by the sample pulses, but impossible to know how those trimpots were setup in the original circuit. Oh well, at least I learnt how to import 3rd party models into LTspice IV.

[dbanner]

Here is the layout for the power supply module. On we go. Next up, the duck's guts.

[dbanner]

Here is the layout for the timing and control module. I do the modular way for possible experimentation with micro at later stages. Maybe some mods or changes too.

[dbanner]

Use two Voltage sources in the simulation that connect together as 'GROUND', 0V. Top V source is VC bottom is VE. This will keep LTSpice happy.

I wasn't much worried about the virtual ground level, was more concerned about the sample delay and tx pulse intervals. That's what I wanted to get at.

[dbanner]

I am currently working on a single side layout. Much work to be done.

[kt315]

kt, is the board you showed at all from the AF108

i suspect no answer https://www.geotech1.com/forums/show...7-Whites/page2

[sinclairuser]

Ok thanks, most unusual , animals swallowing things ?

hi bruce thats the one that has a working frequency of 0.3khz, weird or what?.

[Andi68]

kt, is the board you showed at all from the AF108

[kt315]

you give a link on TO3 (old) case. not same. iwkonik desoldered the board (his pics i put) so he can give pic of the transistor.

[Andi68]

I thought of another transistor on BUY92,
I can not imagine that there should be no more information.
Especially the old transistors are well documented.
This page shows other data ..

https://english.electronica-pt.com/components-cross-reference?ref=BUY92

[kt315]

The BUY92 ist not a TUP- look in the datasheet

http://pdf.datasheetcatalog.com/data.../487271_DS.pdf

this is not same. related to this schematic BUY92 is in TO247-? case. you give a link on more modern one while BUY92 is obsolete of obsolete,
obsoletest, so internet probably had deleted all info on it.
look attentionally again on the board.

[waltr]

. I'm not sure what benefits bipolar pulsing can bring to a beach machine, if any.

No need to have an EFE Sample with bi-polar TX.