CGS88 Bi-directional Router solved!

[wackelpeter]

Hello to all,

I was trying out myself on a stripboard Version of the bi- directional router.

As it's not running i have a maybe stupid question...

When measuring the voltages with a DVM at the Emitters of both regulating Transistors i measure -6,68 at pin 8 and 6,5 at pin 14 of my LM3900...
when´i know measure at pin 9 of the LM3900 between GND and this pin i also measure a negative voltage of -5,95V... is this correct because there's no real ground connected to this module and the measurements on pin 8 and 14 could are referring to the common ground of the psu while pin 9 is decoupled via cap and the op amp and is therefore Floating somewhere around, or should i read there also a positive voltage with ground as common reference?
If the latter would be the case then this means there's a failure in my LM3900 regulating circuit... correct? unfortunately i don't have any other at hand now...

Also i'm a bit curious as my 4007 Chips a called V4007D and i can't find any datasheet for them... my supplier carried these as CMOS Chips of the CD... series...
Anyone know them and can tell me if i can use them...

Thanks in advance for any tips and hints.

And to all who will read this, i wish you a happy new year.

[brock]

The negative voltage on pin 9 of the LM3900 is a problem. It should be positive. I would measure everything relative to the negative output voltage of the regulating transistor to get away from any ground referenced ambiguity.

That said, I'll use your ground referenced descriptions here. Do you have -6.68V on pins 7, 8 and 13 of the LM3900? That seems to be the only thing that could mess up the pin 9 output.

The V4007D should be fine. Here is a link to a minimal data sheet and you can see it is the same as a CD4007. http://www.semicon-data.com/js/geoms/RF/V4/V4007D.jpg

[wackelpeter]

Thank you for your fast reply brock!

Wasn't able to measure again today.. had to drill 208 holes for my new major timing and gating project, which includes a CGS master divider, 2x pulse divider, 2x burst generator, 2x gate sequencer, another 4x gate to trigger converters, 2x and logic, 2x or logic and 2 further cv Mixers...

now a string beneath my elbow is hurting somehow...

one thing i discovered before was that i had 14,5V between both Emitters without the LM3900 inserted and then when inserted it dropped down to 10,5V...

will measure then again with a few modules disconnected from my "noisebox"... could also finger one lm3900 out of working module to test...
maybe it was a bit too much at the edge of what it can provide... i also includes fast 500mA fuses on it's outputs that are somehow sensitive too at a certain amount of current...

i'll report as soon as i have some new measurements made... hopefully tomorrow...

Agin thank's for your Input.

[wackelpeter]

Well finished the new PSU and powered my Serge Switch with it and did some measurements...

first of all the 3904 did not seem to work correct... so i changed it...

now i measured between both Emitters 17,05 V without any IC's inserted and with only the LM3900 it reads 13,79V... at the pin9 of my LM3900 then there are 12,93V...

this seems to be okay at all, but i'm not sure as Ken suggested that without any IC's inserted i should not measure more than 14V but i had 17V... on the other hand these 13,79 or the 12,93 at pin 9 do match the range of the CMOS Chips...

To get those 14V between both Emitters without any IC's i have to put a 22K in parallel to the 10K resistor between both trannie bases... or in other words reduce this to ca.7K...
then the voltage at both Emitters drops with the LM3900 inserted to 11V and on pin 9 to 10V only...

Is that normal that just inserting the LM3900 will cause the voltage to drop down 3 Volts? I mean the are only 10mA on both power rails.... i have to say that at this moment only the LM3900 was powered on the module...

Can someone tell me what voltage at the switching Input 3&6 would activate the switching between both inputs?

At least there's one good result today... my master clock divider worked from the start, except that accidently one wrong resistor made it in my 1k8 box so that the last last stage only had 2,6Volts... but will Change that now...
okay not all LED's are assembled rigth now as i simply run out of them....
but there's a big order placed with nearly 60 LED's and 100 jack sockets...
Will be a nice blinkey Show when completed and space for an extra PSU is foreseen... will see, if i need that... in my divider each LED is consuminh 1,3mA and bright enough for my taste...

[wackelpeter]

well got it working... maybe will tweak the resistors for the +/-7V supply a bit as i only have +/-6,2V left at the power Pins of my 4007...

But it Switches now between both Inputs... don't know what i had done wrong first as i only reduced the resistor on the inverting Input of the LM3900 back to 8k2...
maybe the notes from ken are a bit misleading there, as he wrote for +/-15V Operation both 8k2 have to be changed to 10k... now guess he meant with both 8k2 resistors to be changed to 10k only the 8k2 between both trannie-bases on both circuits the triple-bi-directional-router and the bi-directional-quad-switch and not that one i've changed...

P.S. in lack of a real gnd i didn't had the idea to build myself a virtual ground by pulling two 150k resistors on both Emitters and then connect the both free legs together... so you have a nice virtual ground as reference for measuring within the circuit...