I see some circuit exemples using oscilators (555 and 74HC14), and some others using isolated supplies or the ICL7660 IC.
But all of them have the same problem, current.
After some search on youtube, i come to THIS VIDEO , where Wagner uses this circuit:
Using the simulations, it works really well, but again it have current limits, because all the current are passing on the 100Ohm resistors
After some google, i see this other circuit (See this link)
And finally after some more time of research, i see THIS VIDEO and the following circuit:
*really awesome explanation from the author by the way, big thanks to M Caldeira
As showed in the video, the voltage at the regulated point will be HIGH_Voltage - (zener_voltage + VGS_voltage)
*time of this explanation is 17:00
So finally, i came to the idea of mixing all this circuits together, to have the regulated voltages and the current capabilities of the transistors, and after some hours playing at Proteus, i came to this topology:
Here some things i have observed:
- Without any load and with the opamps disconnected, the voltages are as expected.
- Adding two 1K pots, one between the virtual GDN and V+ and other between GND and V- for simulating loads, the voltage at the rails change a lot if they are unbalanced, so this circuit cant stand for too much components on a single side of the dual supply
- If i connect the opamps, the V+ rail goes to over 700V (see image 5 attached)
- If i connect an axiliary load (arbitrary 500 ohms) to V+ and V-, the voltages come back to normal ranges (see image 6 attached)
As i am just a student and not have engineer degree, my question is, can i use this topology as a dual supply?
This circuit have some impedance mismatch that will cause troubles if i use it? (I have ordered some components to make some tests, but they not arrived yet, so i cant make real world tests right now)
Anyone recomends some changes on this circuit or other options to achieve the dual supply from this single 24v imput?
My goal is to power 5 opamps and have some other components (like voltage divisors between V+ and GND for exemple), and the overall current consumption (other than the auxiliary 500 ohms load) will be no more than 100mA.
Hope i can help other people with this idea too
But all of them have the same problem, current.
After some search on youtube, i come to THIS VIDEO , where Wagner uses this circuit:
Using the simulations, it works really well, but again it have current limits, because all the current are passing on the 100Ohm resistors
After some google, i see this other circuit (See this link)
And finally after some more time of research, i see THIS VIDEO and the following circuit:
*really awesome explanation from the author by the way, big thanks to M Caldeira
As showed in the video, the voltage at the regulated point will be HIGH_Voltage - (zener_voltage + VGS_voltage)
*time of this explanation is 17:00
So finally, i came to the idea of mixing all this circuits together, to have the regulated voltages and the current capabilities of the transistors, and after some hours playing at Proteus, i came to this topology:
Here some things i have observed:
- Without any load and with the opamps disconnected, the voltages are as expected.
- Adding two 1K pots, one between the virtual GDN and V+ and other between GND and V- for simulating loads, the voltage at the rails change a lot if they are unbalanced, so this circuit cant stand for too much components on a single side of the dual supply
- If i connect the opamps, the V+ rail goes to over 700V (see image 5 attached)
- If i connect an axiliary load (arbitrary 500 ohms) to V+ and V-, the voltages come back to normal ranges (see image 6 attached)
As i am just a student and not have engineer degree, my question is, can i use this topology as a dual supply?
This circuit have some impedance mismatch that will cause troubles if i use it? (I have ordered some components to make some tests, but they not arrived yet, so i cant make real world tests right now)
Anyone recomends some changes on this circuit or other options to achieve the dual supply from this single 24v imput?
My goal is to power 5 opamps and have some other components (like voltage divisors between V+ and GND for exemple), and the overall current consumption (other than the auxiliary 500 ohms load) will be no more than 100mA.
Hope i can help other people with this idea too
Attachments
-
172.5 KB Views: 3
-
103 KB Views: 3