wrong MF voltage

Testing/Troubleshooting
1

Hi,

Tried a lot…but nothing worked..somehow…

Made the Motorfader module and i wanted it to test it with the example…but somehow…my voltage-regulator (LM317-220) is not giving the right voltage (what should be 8V (after adjusting with 1k-pot)according to the documentation) out…

Don’t know quite what’s wrong…

Used the .pdf from the site, and every diode is placed in the right way…but something strange is going on…

Measured the voltage of my powersupply on the circuit and that’s was all above 8,5 V on my capacitors, until it went out my LM317-220 then the voltage became 2.2 and 1.5 V.

Soldered it in the same way as the image on the site.. so thought this should be okay…

What’s wrong if everything is okay soldered…And is the LM317-220 indeed a voltage regulator as i claimed  it to be or…is it a current regulator…???

What’s an optional suggestion for trying to get 8V…and the motorfaders running,…A 78L08 or 78L09 (with adjustment?)…

Some little question still:

Is it possible to burn a 16F84A on the JDM? And if yes, how is this achievable…(by using a second socket…and hereby soldering the right legs of the JDM to the optional socket?)

As I read somewhere here on the Forum that it should be possible…to also use 16F877A…and to burn with JDM…but i wasn’t able to…although I was able to burn 18F’s and 16F’s…what’s the difference between the A type and the "normal 16F877?

Somebody…???

Thanks in advance…

Erik

2

So much absolutely different questions in one posting? So, am I allowed to pick out the one I like? :wink:

(such cross-postings are making the search function of the forum inefficient)

LM317: no idea

78L08 and 78L09: absolutely not recommented, especially the L type will blow away immediately, remember that the current drain can be 1A and higher

PIC16F84A: read the original JDM page - the JDM was originally designed for the PIC16x84x - the link can be found at the MBHP_JDM page

PIC16F877A: new flash technology, it requires different programming settings in IC-Prog. The rest is compatible to the PIC16F877 (if users would sort their postings better, you propably would find this answer with the search function… ;-))

Best Regards, Thorsten.

3

Sorry for the different postings…

But I was a little afraid that I would overwhelm the forum, if  i posted three topics…

(such cross-postings are making the search function of the forum inefficient)

Probably your right…but that it also depends how you search…because if you typ…the problem you search with keywords as 16F877A or voltage-regulator (ie by name or so…) or 16F84A…you will always come to this post…maybe you don’t need it then…and is it not specific enough for  the thing your searching…it is included…Or am i wrong now? :-/

LM317: no idea

I also can’t get grip on this..but you have though included this LM317-220 in the orderlist …or not?

Nevermind…found something…the LM317-220…can regulate voltages from 1.2 to 25 V…with the ingoing voltage raised by 3 V (makes 28V max)…But it also can’t handle/output more than 1A…refering to the next thread  ;)

78L08 and 78L09: absolutely not recommented, especially the L type will blow away immediately, remember that the current drain can be 1A and higher

And the large version (A 7808 or A7809)…would that also be blown away?

PIC16F84A: read the original JDM page - the JDM was originally designed for the PIC16x84x - the link can be found at the MBHP_JDM page

I know…I already did…But the guy seemed to have change his site…so you have also a kind of “broken” link in the site here…

Just for the record…:wink:

Searched his whole site, but couldn’t find this conversion method (which have ones already seen here) anymore…

I think i finally gone check the pin story myself…enough documentation to find…

But thanks anyway… :wink:

Thanks for the quick reply…BTW…don’t stay up too late…huh?

I was surprised to see you still working at 5 in the morning…

Thanks…

Erik

4

mmm I use a 7806 + a 4V zener diode to make the 10V psu for the MF… I only have 2 MF, so it will not be enough if I have mor MF?

5

Erik: concerning the article: you will see the problem once a lot of people answering to different questions… you will lost the oversight. Most of your questions will never be answered

Pilo: I see no reason why to use a 7806+4V Zener before the LM317 - the LM317 is nothing else than a LM78xx with adjustable output voltage.

In general the LM317 should be the most prefered voltage regulator for the MF module, due to the adjustability. I cannot recomment any other solution, since some motorfaders require a different driving voltage for best performance (from 7.1, 7.2, 7.3 … 9.0V) - you have to try this out!

Erik: if you are not able to get the LM317 working, download the datasheet and try to build a minimal circuit, just to ensure that the chip is still ok. It doesn’t really make sense to try out different regulators (see above)

Broken Link: could you please specifiy exactly where it is? I just tried it again (I clicked on the link at the top of the MBHP_JDM page) - it works and it points to exactly the same page like 3 years before

There is no conversion method, the original JDM programmer was designed for PIC16F84, just compare the original schematic with the MBHP_JDM schematic and you should notice the “conversion method” (just only the pinning is different, and nothing else)

Best Regards, Thorsten.

6

Pilo: I see no reason why to use a 7806+4V Zener before the LM317 - the LM317 is nothing else than a LM78xx with adjustable output voltage.

I was too lazy to buy a lm317… :-[

But I thought 8V should be ok for alps, I’m going to try with a lm317 :wink:

7

I had to swap the 100ohm resistor for 75ohm, for the regulator to get 8v (not enough range in the trimpot)

8

I too had to change the lm317 trimpot to a 10k one and swap the resistor to a 1K to get 8V (and more ;)) for the MF…

9

Another thread without an ending ???

did you get MF board working, Erik?

BTW, find a zip on this page, with details on a JDM programmer “JDM ZIFF” and “JDM ALL” use the PCB titled ‘JDM by corona’ This will work for the old PIC16F84

I didn’t want to etch a board, so I built it on perfboard, but looking back, it would be quicker and easier to make a PCB using the ‘press’n’peel’ method.

let us know how it all went. (long time, no post… I hope Erik hasn’t given up! :-/)

edit… oops, here’s the link! http://web.tiscali.it/digitalfreesat/interface.htm

10

Hey folks!

Just read this thread because i have a similar problem with the mf Modul!

Just could get about 0,5 V out of it.

I have two mf boards, none works.

To specify the error, i measured some values.

The Voltage reference(lm 317) which should be 1,5 , is only 0,45 V. (the same on the second mf board)

Measure results: Ground - Input lm 317 = 10,8 V (a little bit less, i tried another power supply with 13,5 V = the same results)

Potentiometer 0 Ohm: Input - output lm 317 = 0,45 V

                                   Input - adjust lm 317  = 0,25 V

Potentiometer 1 kohm:Input - output lm 317 = 0,45 V

                                   Input - adjust lm 317  = 0,45 V

I didnt try other values at r1, because it must be significantly higher than it is.

It dont minds whether position the potentiometer stands, its alway 0,45V output at c4.

I really cant believe that all two of the lm317 are gone into the nirwana.

I will try a new lm317 on a printboard.

But its a really strange behaviour. Hopefully someone could help me out with some tips, or exprenciences from someone who had a similar prob and solved it!

thx in advance

Schoko                                

11

Hi Schoko,

Yes, try it on a breadboard step by step, this should give you a feeling which components are working (and which not)

Best Regards, Thorsten.