I would agree. But you'd have to have a very precise amplitude in the sine wave. What's the accuracy of your true rms voltmeter in the amplitude range and frequency that your sine wave is.
swap the semiconductors for their complementary parts.
9610 >610
9240>240
bc550c > 560c
bc546c > 556c
Then turn around (invert) D1 & Q8 & Q9
swap C2 around.
swap the +ve & -ve power leads.
All the regulators can be changed in polarity by applying the same swapping rules.
The PCBs can be used for either polarity.
The -ve regs should be slightly cheaper, certainly the parts are more readily available.
There may be a slight increase in performance due to all N channel FETs being used.
9610 >610
9240>240
bc550c > 560c
bc546c > 556c
Then turn around (invert) D1 & Q8 & Q9
swap C2 around.
swap the +ve & -ve power leads.
All the regulators can be changed in polarity by applying the same swapping rules.
The PCBs can be used for either polarity.
The -ve regs should be slightly cheaper, certainly the parts are more readily available.
There may be a slight increase in performance due to all N channel FETs being used.
salas isn't around for a few days, you'll have to be patient.
Thank you guys.
The shunt part can be used without any component changes, just switch the output and ground nodes, and use a negative CCS.
Iko, if this schematic is accurate, I think C1 and C4 would explain the strange rise in impedance. The MOSFET will have to sink large currents out of these caps before it can make any change at the feedback nodes.
http://www.ikosonic.com
However I see this is absent on the second schematic.
- keantoken
Iko, if this schematic is accurate, I think C1 and C4 would explain the strange rise in impedance. The MOSFET will have to sink large currents out of these caps before it can make any change at the feedback nodes.
http://www.ikosonic.com
However I see this is absent on the second schematic.
- keantoken
if i knew i wouldn't ask seriously i don't know, i know there are many versions of this project, what interests me is one that is capable to feed the dac with a voltage of 5-5.5v @ 100-200mA, don't even know if is available something like that... i used with very good results the HV version so i wanted to try the LV with this new project.
thanks
seriously i don't know, i know there are many versions of this project, what interests me is one that is capable to feed the dac with a voltage of 5-5.5v @ 100-200mA, don't even know if is available something like that... i used with very good results the HV version so i wanted to try the LV with this new project.thanks
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if i knew i wouldn't ask
thanks
I use this for BII, only change Vin-Vout 7-10V difference target Vout, R12 use 1K trimmer for 5.5Vout, you can get better perfomance using more current: I use ca. 500mA
Enjoy
P.S. AndrewT don't be so rude, the thread is too long.
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Hi Andrew
Reading a thread about pedja´s buffer, I read your post " even those that design and build discrete regulators sometimes use two positive regulators rather than design a + & - pair.
The only down side to this twin positive regulator is the requirement for dual secondaries and dual bridge rectifiers.
Most will accept the extra cost because of the technical benefit accruing from +ve regulators."
Do you also recommend the use of two positive Salas regs if we use separated secondary windings in the TX ?
Reading a thread about pedja´s buffer, I read your post " even those that design and build discrete regulators sometimes use two positive regulators rather than design a + & - pair.
The only down side to this twin positive regulator is the requirement for dual secondaries and dual bridge rectifiers.
Most will accept the extra cost because of the technical benefit accruing from +ve regulators."
Do you also recommend the use of two positive Salas regs if we use separated secondary windings in the TX ?
Numbers are going down fast, from 120mOhm to 28 already. Now if you used a much higher hfe 560C instead of 2N4403 as error amp and a CCS instead of its resistor load plus 4 wires connection like we usually do, things could go even better? We just stick an LED between the ref resistor and its CCS for drift, the diode at the emitter worsens performance. Just Use a JFET that has <0.6V pinch off, and you won't need an extra silicon junction drop, vbe will suffice.
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