Barracuda.....update(2)

[sinclairuser]

the versions of barracuda in this thread are for archive purposes only, please see the barracuda ledgend thread in schematics.
the versions in this thread were done before alexismmex reverse engineered the barracuda, and apberg drew the current board,following this thread causes more questions than it answers.
there is nothing missing, or left to understand about this detector, its all done in the other thread.
if you are looking to mod it then again start with the working board, maybe this thread should be locked, as it will only confuse the novice.

[mohandes]

any body have pcb fesign and oast it here ?
i make last barracuda but have meduim detection ( not good ) , and i will make it .
please put all here
regards

[dom44]

i built the Barracuda from this post and it does work!

http://www.geotech1.com/forums/showthread.php?p=123068

[hoppy1166]

CD4538 PSPICE

I'm a Newbie to this and all forums, I need to find the PSpice for the CD4538/MC14538.
Can someone help me out?

[nick_f]

Hi All,

Since the Anchor Electronics web site is down, you can still check its previous content using the Internet Archive.
Here is a link to some reviews of the Barracuda: http://web.archive.org/web/200210092...com/field.html

Regards,
Nicolae

[Noemio]

what about a PIC?

Hi all,

if you wish i could send you a hex file for a PIC16F84 with outputs for fets and mosfet.
Just tell me wich ports of the microcontroller I should use (but there's no difference, just to have a nice PCB) and the timings you prefer.
Could be needed to add a couple of transistors to shift from +5 to +12 and, I think, ICL7660 could no need sync and run freely.
I am rather interested in Barracuda PI too.

[porkluvr]

see the PI.zip

Hello Geo -

I'm Sorry you couldn't find what you need. Use the CD14538B symbol and model. Look at the Goldscan setup.jpg in the PI.zip file for some setup tips.

CD4000.lib.txt contains the model, and the CD4000 folder contains symbols.

Not all "4538" type devices are the same; some manufacturer add hysteresis to one input or another. For instance, ST's HCF4538 has hysteresis on both inputs, but has a more limited range of RC components that are acceptable, compared to, say, Fairchild CD4538, which has no hysteresis that I am aware of.

Motorola's contribution is MC14538, and the CD14538 is from Texas Instruments. The TI datasheet specifies hystereses on both inputs, but I absolutely cannot vouch for the accuracy of our CD14538b model. But it's all I have. The simulation model is good for avoiding stupid mistakes, but of course it is not guaranteed to provide a realistic prediction!!

Oh, and it runs pretty slow. I use the reset line to keep the oneshots disabled until the LM555 starts firing, because simulations seems to run a little faster that way. What I like about the Barracuda, was that the simulations are very fast compared to Goldscan or Hammerhead, for what it's worth.

Good luck, and let me know if you still need anything.

[Geo]

Hi porkluvr.
I want to run the new schematic at the LTspice, but there is not the CD4538 in the add components for the sample. Can you make it and to send here to me, or if there is any other way to take it.
Regards

[Geo]

Geo, I thought you were talking about real life problem with FET. My sims run well (except for not having enough control over Barracuda timing).

Your problem is very strange. Make sure the power supplies are uniformly labled, and correct attribute parameters set for digital parts. Remember that +5V and 5V would not be interpreted as the same net.

I have idea. Send me a copy of your netlist. Maybe I can analyze that. Like so: View > Spice Netlist, then CTL+A, CTL+C and paste into email. You can get my email from my profile information.

Sun's coming up soon, I better go.

Hi porkluvr. Sorry for late answer, but i am very busy this time. I play (when i have time) with your file so there is not reason to send it to you. I believe after 3...4 days to find the time to finish the detector. If this time i should be error again then i will make a schematic and i will email to you to run it to the simulator
Best regards and Happy New Year

[porkluvr]

O0ooh, one more thing, not that anybody is is interested: remember that you can 'do' many things with simulation models that are not generally accepted as good practice, such as, operating HC221 from a 10V supply.

Operating levels and 'Level shifting' parameters must be considered carefully and intelligently. The spice model for HC221 will probably not complain if you apply a virtual 10V supply, but the real thing will very likely go up in smoke.

Do not get complacent just because your simulation 'runs'.

[porkluvr]

view the netlist?

Geo, I thought you were talking about real life problem with FET. My sims run well (except for not having enough control over Barracuda timing).

Your problem is very strange. Make sure the power supplies are uniformly labled, and correct attribute parameters set for digital parts. Remember that +5V and 5V would not be interpreted as the same net.

I have idea. Send me a copy of your netlist. Maybe I can analyze that. Like so: View > Spice Netlist, then CTL+A, CTL+C and paste into email. You can get my email from my profile information.

Sun's coming up soon, I better go.

[Geo]

Check your 2N3819 connections. There are differents 2N3819 pinouts used by different manufacturers. You probably assume SGD but actually have GSD, or vice-versa.

Also, 2N3819 is probably not the best choice for a 2N5485 substitute because VGS(off) is a little high.

Hi porkluvr.
The connections of 3819 are good. Today i will try to connect in series with gate a resistor (56.... 100k). If i will not solve the problem then i will change the 3819 with BF245B.
I will try it later. Now i have problem with the TV antenna and i must repair it (i can't hear my sons)
Regards

[Geo]

Hi Alex.
Maybe all your schematic to work fine, but when i simulate the out of 40106 direct to 2N5485 then the pulses are not good. Maybe 40106 have not the ability to direct load the 2N5485. The same problem i have now with the 4538. Alone are working perfect but when i connect to the 2N3819 the pulse it falls. Today i will connect a resistance in series and i believe to finish the problem.
Regards

[Alexismex]

Hello forum
Porkluvr I have revised the schematic in my post 45 is OK 100% I post the front end i use for the two channel .
BEST WISHES 2008

[porkluvr]

.... when i connect the sample pulses to the "Fet switch" the pulse goes to -1....+2V so can't turn the Fets on and Off. I can't understand why????
I use 2N3819. I have similar problem if i connect the pin10 (out) of the 4538 direct to the Fets......
Any idea........
Regards

Check your 2N3819 connections. There are differents 2N3819 pinouts used by different manufacturers. You probably assume SGD but actually have GSD, or vice-versa.

Also, 2N3819 is probably not the best choice for a 2N5485 substitute because VGS(off) is a little high.