LOOKING FOR GOLDSCAN 4 Schematic.

[Jose]

Hi all
I use only two types of diodes in my GS4 homemade.
Where it says Germanium (OA85), I use another 1N60 germanium.
Otherwise either the source or the time base, I use 1N4148, and works well.
The original source of GS4 was a bit noisy, then install a 7660 copy of HH2, working in sync with the pulse generation, attachment scheme, the diodes used are 1N4148.
Regards, José

[ABDW9]

Peace be upon you my brothers
It seemed to me not to me but to use Germanyum diode instead of Schottky diode BAT85 and BAT49 the absence of this kind at all, what do you think
I have seen that germanium diode of the same characteristics of BAT Schottky diode

[porkluvr]

Maybe my "original drawing" is messed up (I've been guilty of messing up perfectly good work before) but I see a potential problem with the charge pump in my previous post.

Apparently, the maximum voltage that can be obtained with -12V input is only about +3V. Doesn't matter what diodes are used, 3 Volts does not make a good input for LM78L05.

I think that 555 duty cycle (dc) (about 95%) is the boogeyman. My LM555 model is not exactly same as the specified TC555, but it should make a reasonably valid point.

The original circuit is simulated at "A". The bottom trace is voltage output. The top trace is diode current, (zoomed in at about 5ms).
************************************************** *******

In "B" I made changes in the 555 circuit to obtain ~50% duty cycle. It requires adding one diode and changing two resistor values. Those R values should give close to the same 555 output frequency as before, but with a more symmetrical waveform.

Now the charge pump can drive to +11.4V in about 22ms.

Well, er, I also changed R11 and R12 to 4.7kΩ at "B". That reaches peak output more quickly, but 10kΩ will work fine. (oops, but not a big oops)

edit: OF course the idea for adding the 1N4148 diode to modify dc is not my own. Look at Eric Foster's CS6PI circuit and you will see the same scheme used in the tx oscillator. There is another common method for getting symmetrical 555 output (look at the Tesoro LOBO circuit) but that would require a little more PCB modification. And for that matter, it is not necessary to drive a charge pump symmetrically, but I think it helps.

[ODM]

The peak current is usually several times higher in charge pumps and switching converters. If the ge diodes are rated for pulsed power, it's fine, not all ge devices are.

[ABDW9]

I think you would be better off to use 1N5817 schottky in the power supply. That is a relatively high peak current application and most germanium diodes won't like it.

You can find 1N5817 just about everywhere.

Thank you my brother porkluvr on this information
But what if a ready measurement must read 500mA not affect this type of diode in which bears only 10mA, I think this is a big difference will come okay
You thanks and appreciation

[porkluvr]

Thank you my friends have explained the way in the hope that trying hard to find a BAT, but I will be using Germanium diode ..
Thank you all

I think you would be better off to use 1N5817 schottky in the power supply. That is a relatively high peak current application and most germanium diodes won't like it.

You can find 1N5817 just about everywhere.

[ABDW9]

Thank you my friends have explained the way in the hope that trying hard to find a BAT, but I will be using Germanium diode ..
Thank you all

[Davor]

Schottky diodes can be replaced with germanium diodes, provided you have them around. Trouble with low barrier voltage diodes is that they tend to leak in reverse polarisation, so you have to know what you need to achieve, and find some type that works as required. BAT diodes are quite ubiquitous, and if a schematic calls for these types just go for it.

[Jose]

In the scheme of PaPa Alex, post number 4, page 1, and OA85 1N914 figure.
The replacement OA85 is 1N60.
The 1N914 replacement is 1N4148.

http://www.datasheetcatalog.org/datasheet2/6/0es8jh12sejk0sfjx66qcdztqfcy.pdf

Jose

[ABDW9]

Try getting germanium diode, 1N60 I got worked well.
Jose

My dear
Goss salute you and thank you
But is it possible to explain more
Do you mean that I use Germanyum diode 1N60 to work instead of bat49 & bat84
Thanks

[ABDW9]

You can replace 1N914 with 1N4148 as they are basically the same thing.
BAT49 and BAT85 are schottky diodes and their barrier voltage is considerably lower than regular silicon diodes. You can't replace them with 1N4148 because their role is to protect JFET gates that also have a somewhat lower barrier voltage than silicon diodes.

Thank you very much my brother
For this illustration you all greetings
But this bat49 & bat84 diode is to facilitate available to us how to treat these pulp
Is there a replacement? .....

[Jose]

Try getting germanium diode, 1N60 I got worked well.
Jose

[Davor]

You can replace 1N914 with 1N4148 as they are basically the same thing.
BAT49 and BAT85 are schottky diodes and their barrier voltage is considerably lower than regular silicon diodes. You can't replace them with 1N4148 because their role is to protect JFET gates that also have a somewhat lower barrier voltage than silicon diodes.

[ABDW9]

Hello all, my brothers
Not only left last step I
I can not get this diode


BAT49.pdf
BAT85.pdf
1N914.pdf


Can I use 1n4148 instead of them?

[makedonyalı]

GS IV 1x1 large bobine oM be