MC34063, LMC6484 and nuts..

[ivconic]

I haven't payed any closer attention on those voltage converters so far. Those are more often present in various electronic devices in last decade.
Usually works good and i haven't neither one case of repairing related to this thing.
Now i am up to build detector with it and want to know details about those two L in circuit. I read few datasheet and founded no details.
This particular stage is taken from some modded White's schematic.
I intend to build that handmade and already prepared pcb and all the components.
* Must know how to make those two coils. Any idea? Any help?
Another thing;
* damn LMC6484 is there also. I simply can not find it in local shops!
There are 4 LMC's in this particular design.
LMC6484 is CMOS Quad Rail to Rail and Output opamp. What closest equivalent i should use?
And i mean closest from old series - not some modern ic's also not available!
* And last question is 1N5819, Schottky Barrier Rectifier (40V,1A)!
Could it be somehow voided ? Any harm from ordinary diode? Any better replacement?

I will appreciate help; hints and tips!
Regards!

[nickel_n]

1N5819 and replacements

http://www.altronics.com.au/index.asp?area=item&id=Z0040
i hope that will help
IN5819 Schottky Diode 40V 1A
DO-41 Package

Suitable replacement for OA90, OA91 or OA95 diodes.
http://www.altronics.com.au/index.asp?area=prod&grp=376
info on MC34063

[Altra]

Hi Ivconic,

I have used the MC34063 in the past. In general 100uH to 400uh for L1, a torroid is best for noise, and it needs to be heavy enough to handle the current. L2 is a series low pass filter and can be almost any choke over 10uh. 1N5819 is used because of the fast recovery and low forward voltage drop. You can find the inductors and diodes in switching power supplies salvaged from old computers.

For the quad op-amp. Try TL074, TL084 (old), better TLC27M4 used in 1280x, 1265x

Regards Mark

[Aziz]

here is a good paper on MC34063:
http://www.intusoft.com/onsemipdfs/AN920-D.pdf

Aziz

[ivconic]

THANK YOU VERY MUCH FRIENDS!

[porkluvr]

Ivconic, if you use older opamps designed for +/-15V power supplies you should not run into a problem with generating a virtual ground as shown.

However, if you use the single 220uF filter cap on the negative rail (and without one on the positive rail) your positive voltage will shoot up towards 14V before the circuit settles down to a symmetrical +/-7V and that could be a problem for low-voltage opamps. I'm thinking that 2x 100uF caps - one to each rail- would minimize the possibility that happening. Or, 2x 220uF etc.

[ivconic]

Thanks Porkluvr, that is part of schematic of 6000 clone i am planing to make in near future. That's why i asked question - to clear up some doubts.
Thanks!
Regards!

[rael]

MC34063 parameters calculator link:

http://ukpyr.narod.ru/calc_mc34063.htm

[wlewis]

For the quad op-amp. Try TL074, TL084 (old), better TLC27M4 used in 1280x, 1265x
Regards Mark

Hi Altra, just want to make sure I got this straight.. the TL074 etc.. can replace the LMC6484 ? I want to build the idx-pro. Also, I don't see the LMC6484 on the pcb board by silverdog - why is that? Was it circumvented or what?