Delta Pulse

[amtech2005]

Delta Pulse

Hello , KT315 . I like the Condor 3 the best !!!!!!!! Thank-You for posting all these photos , they look like very good machines !!!! And I am sure they cost much less than the "Overpriced Nexus"........Bye..........Eugene

[kt315]

Cornet 7250 (not so new model though)

http://rapidshare.de/files/40237707/cornet7250.zip.html

[kt315]

good day to all. I am realizing the deltapulse. is possible to replace LF357 with LM318? Thanks for the answers
excuse my english

no, it is not. you must use only JFET input op amps in this schematic. try TL081 it works of me.

[Mullihaka]

TR4 / TR5 versus component values

Hi,

I have checked the whole Delpa Pulse forum thru several times, but couldn't find what I was looking for. The timing of TR4 and TR5 in my DP are different form the often seen timing diagram. Values of my DP are in large numbers in the diagram below. I use 4528s instead of 4538. I believe they are the same, the 4538 being just a bit more precise. The data sheet of 4528 gives formula t = R*C*0.3, where t is pulse width [s], R is resistance [ohm] and C is capacitance [F]. When I compare the values from the formula to measured ones, they are of same magnitude. So, I believe the component values in the picture below match with the data sheet formula.

What would be the values for resistors and capacitors around the two 4538s to get the timings like in the diagram? Yes, I could find them myself. I'm just wondering if I have missed the correct component list or if the timing diagram is of a DP with "tuned" performance.

All hints appreciated.

[kt315]

can you digitally shoot all markings on the capasitors C4 and C5? is not clear from your comment what you did stay on your PCB really.

[Mullihaka]

C4 and C5

I can't take a picture right now, but the capacitors are 1.5nF. I have been playing with components since 1980., so I'm pretty sure. I also measured them with my capacitance meter.

The funny thing is that the formula in the 4528 data sheet gives the same result as measurement with the oscilloscope.

Could it be, that 4528 has some undocumented feature which makes it behave in different manner from 4538?

I need to get 4538s, I just built the DP from the components I had on stock.

[kt315]

Could it be, that 4528 has some undocumented feature which makes it behave in different manner from 4538?

I think it is a cause. 4538 gives me a diagram accordingly to original one.

[porkluvr]

Hi,

The data sheet of 4528 gives formula t = R*C*0.3, where t is pulse width [s], R is resistance [ohm] and C is capacitance [F].

Off the top of head, I think that 4538 devices have a direct t = R * C ratio, with no 0.3 factor involved. (And, by the way National Semiconductor's CD4528 datasheet states: t= 0.2ln[Vdd-Vss](RC).) Little details could make a difference.

Look up natural logarithms to find out how to apply "ln".

But also, not all 4538 devices are the same. Besides having a slightly different timing formula ( compared to NS CD4528 ), some " 4538 " manufacturers specify minimum values for R, or C, or both. It is a good idea to read the datasheet for any specific device that you are using instead of generalizing! MC14538, CD14538, HCF4538, and CD4538 are all very close - but there subtle differences.

There is no "the" 4538 datasheet unless you are being specific. That probably goes for 4528s also!!

[Mullihaka]

Thanks a lot! Just found the same factor "0.3" in the 4528 data sheet. Better read the data sheets first than jump straight into experiments. No harm done, only couple of days spent.

[kt315]

from these proportion formula you can divide 45us/15us=3 and on the digit to multiply C5 (or what you want to change).

for example. C5=1,5nF*3=4,5nF ~4,7nF

hh

[kt315]

people, I need in fully Comparision Table for the article I am writing on DP.
please add to the table IC's what you are knowing about.
---

D4 - КР574УД1, К140УД23, TL081
D5 - TL082, TL072, LF353, LF412, LT1057CN8
D6 - TL082, TL072, LF353, LF412, LF442
D7 - TL082, TL072, LF353, LF442, LT1057CN8, TLC272, TLC277, TLC27M2, TLC27M7

[Max]

people, I need in fully Comparision Table for the article I am writing on DP.
please add to the table IC's what you are knowing about.
---

D4 - КР574УД1, К140УД23, TL081
D5 - TL082, TL072, LF353, LF412, LT1057CN8
D6 - TL082, TL072, LF353, LF412, LF442
D7 - TL082, TL072, LF353, LF442, LT1057CN8, TLC272, TLC277, TLC27M2, TLC27M7

Hi,
crossref ?

For D4 (tl081) you could use also TL071, LF351 (now discontinued), NE5534, LM308...could be even better there.

D5,D6,D7 could use also 27M7 or 27M2... also TLC2262 could be useful there, even better than originals. You can use also TS27M2, TS27L2 that are same of TLC stuff.

I've not tested all these things there but think they could work just fine on DP.

Kind regards,
Max

[kt315]

thanks Max! NE5534, LM308 are not JFET input opamps
I have read some people had did try but got a bad result testing NE5534. the preamps intend only JFETs I think because its sample and hold nulling drift balance principle.

[Max]

thanks Max! NE5534, LM308 are not JFET input opamps
I have read some people had did try but got a bad result testing NE5534. the preamps intend only JFETs I think because its sample and hold nulling drift balance principle.

Well yes, they are not good in sample and hold circuits... you're right.
I simply forget about sample and hold there!

Much depends on capacitor and timing too... but , of course, jfet have superior advantages there... much higher input impedance.

PS: better than TL081 then... could be an AD820 there... what do you think ?

Kind regards,
Max

[kt315]

has slow Slew rate low noise is well. for preamp will be not serve.
but probably will be good for VLF's like TGS.

anyway thanks.