Replies to Minipulse Plus

[sinclairuser]

is this progressing at all, i was going to do this as the next project, but i'm getting itchy fingers, so if not i'm going to build something else in the meantime.

[satdaveuk]

is this progressing at all, i was going to do this as the next project, but i'm getting itchy fingers, so if not i'm going to build something else in the meantime.

Dont hold your breath waiting, I also got all the bits ages ago, since built the pikini lol , thinking it was a question of running before walking on this project like so many others on here

[Davor]

Qiaozhi is busy lately, so just be patient
I'm waiting too.

[Qiaozhi]

Both Silverdog and I have successfully built the most recent version of the Minipulse Plus. There are a few errors that need to be corrected in the posted files, so please do not attempt to build the design as it currently stands.

To differentiate the Minipulse from the Surf-PI and Barracuda designs, I have decided to make some updates, such as incorporating a 2-stage pre-amp to allow earlier sampling.

I'm very busy at the moment, but hopefully can find some time soon to get this project moving along.

[Davor]

Thanks.

[bernte_one]

hello,

are the any project updates?
i feels so boring and would start something new
corrected layout, new circuit or some available boards?

regards from rainy east germany

[Qiaozhi]

hello,

are the any project updates?
i feels so boring and would start something new
corrected layout, new circuit or some available boards?

regards from rainy east germany

Sorry. I know there's been a long wait.
In fact last night I actually did some work on the next revision, and hopefully I can get the design finalised in a few days. Next I'll send over the Gerber files to Silverdog to get a few test boards made, and .... will keep you posted.

[bernte_one]

that are good news carl, so i stay in standby mode

[Qiaozhi]

The MiniPulse Plus (Rev-B version) has taken a few steps closer to completion.
Tonight I managed to complete the component placement and completely routed the board ... without any DRC errors.
Sometime over the next couple of nights I plan to generate the Gerber files and get these off to Silverdog.

This latest version has the following features:
1. A 2-stage pre-amp, which will allow earlier sampling.
2. Diode pump circuit replaced with an LT1054, and synchronized with the transmitter. Both Silverdog and I had some unreliability problems with the original circuit. The battery pack can now drop from a nominal 12V to below 8V before the +5V supply starts to drop out.
3. PCB size reduced to 3.5" square.
4. There is now only one on-board trimmer. This is the setting for the minimum sample delay.
5. Battery check circuit eliminated. Silverdog persuaded me that this was not really necessary, and it was difficult to calibrate without a bench power supply.
6. There are separate connectors for TX and RX to allow the use of a DD coil if required.
7. The loudspeaker amplifier is now the default output, which simplifies the wiring for the headphone socket.

All of the above changes were made after building the Rev-A version, and deciding that there was little to differentiate the MiniPulse Plus from either the Surf-PI or the Barracuda. Hopefully these improvements will make this a worthwhile project to construct.

More later ...

[sinclairuser]

thanks george, following with interest.

[Davor]

The board is beautiful
The only component that may receive a bit of TLC could be the large electrolytic capacitor, as there is no room to bend it on a side ... unless the test point pin is omitted.
I like it

[WM6]

The board is beautiful

I like it

Me too. Exemplary design.

Qiaozhi you say that there is now only one on-board trimmer. What sort of outer controls are foreseen for Minipulse now?

Are there outer meter (something like VU-meter) provided?

[Qiaozhi]

Me too. Exemplary design.

Qiaozhi you say that there is now only one on-board trimmer. What sort of outer controls are foreseen for Minipulse now?

Are there outer meter (something like VU-meter) provided?

The external controls are Audio (which sets the threshold) and Reject (which sets the sample delay).
Apart from that, there's the On-Off switch (can be incorporated as part of the Audio control), headphone socket, and coil connector.
There is no external meter. Why would you want that anyway?

[WM6]

There is no external meter. Why would you want that anyway?

Just asking, sometimes it could be more sensitive than audio.

[Qiaozhi]

I've just sent the Gerber files to Silverdog.