question about the generator (-5V) TGSL

[gost373]

Hello ,
regarding the tgsl can you tell me
where is the converter circuit (-5V)
and explain how it generates ( -5V )

[waltr]

Hello ,
regarding the tgsl can you tell me
where is the converter circuit (-5V)
and explain how it generates ( -5V )

Find and download Don's TGSL_101_part1.pdf document.
On the schematic the -5V 'charge pump' is section 3.
The two transistors, TR7 & TR8, are driven from the TX Clock divided by U100 then rectified by D6 & D7.

[gost373]

Thank you for the answer, I downloaded the doc TGSL_101_part1.pdf but there is something that escapes me!!!
I did a simulation with Multtisim, on the point ( A )
noted with the voltmeter +5V if I measure the same point with the oscilloscope, since the signal varies I can actually assume that it has -5V. Now if I take the measurement on point B no voltage value !! so I assume that the measurement is done
well in point (A)? .


see attachments.


voir pi?ces jointes.

[waltr]

Point A should have a square wave of 0V to +8V. Is power connected to U1, the divider chip?
Point A needs to be measured with a scope NOT a Voltmeter since it is not DC.
Point B should be rectified and filtered -5V (so so) DC.

[gost373]

Good evening, I made a new analysis with electronics Workbench,
see jpg attachment. at point A +5V at point B + 8V
is the simulation correct?

[Carl-NC]

No, point A should have an amplitude of 8V. As it is, the PNP will never turn off. MultiSim may be simulating the 4024 with a digital model set for 5V. You either need to figure out a way to tell it to use 8V, or reduce the battery from 8V to 5V.

[gost373]

Thanks to both of you for responding!
in the last message Carl told you, MultiSim can simulate the 4024 provided you find a way to set the voltage of this circuit, I have been looking for a while in the multisim settings to find how to change the voltage of the 4024 cmos circuit , but I can't find it! even by going on google !!

[Carl-NC]

Then just set the battery voltage to 5V, then everything will run at 5V and it should work. The inverter voltage will be a little less than -5V.