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John Linsley Hood Ripple Eater - Part 2

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#184
Hi
If the current limiting is done by a 78/79xx or 317/337 then you will not need the CL section in the JLH, in which case 12V IN for 12V OUT.
If you are using the onboard CL, then the extra voltage needed is set by the value of the CL's emitter resistor and it's voltage drop, plus the saturation voltage of the CL transistor. In other words, it will depend on the load current mainly.
It will be typically several hundred mV in that case.
Alex
 
#190
RE JLH PSU Add-on.
As a matter of interest, if they are preceded by 3A regulators such as the MC78T05, and MC78T12 with the Current Limiter section bypassed, and the regulators are doing the current limiting instead , they will work well at +12V 2A and +5V 2A. For best performance at +5V, or even as low as +3.3V, the 10K resistor should be replaced by a Current regulating diode such as the J506 (1.4mA nominal), or a selected FET such as the 2N5484 with Gate and Source tied.
For use with the current limiter section, the main electros should be 2 x 2,200uF in parallel. A 2,200uf 10V low ESR, and a normal 2,200uF is recommended for a neutral sound with Audio.
If used with the Current Limiter section bypassed, a 4,700uF 10V low ESR and a 4,700uF
16V normal type is O.K. too. This is what I am using with a +12v 2A and +5V 2A PSU.
With the CL section bypassed, the voltage drop wil only be several mV due to the copper traces of the PCB tracks, and this will depend on the current being drawn.
At voltages higher than 20V, the CL transistor and the transistor with the 33 ohm emitter resistor should be fitted with small heatsinks.
Further information can be found at Greg Erskine's web site.
Sandyk

Greg's Web Site (Click on Power Supplies.)
 
#193
As Jon says, there are presently no plans for another GB.
For those who are capable of etching a PCB, there is full information at the link I provided in post 190. The design there is for a DUAL PCB which is capable of being used for a + and - supply , or 2 supplies of the same polarity, provided that the appropiate devices are used, and capacitor orientation is corrected if need be.I posted that additional information in response to a PM from DaveK .

SandyK
 
#195
Greg's Web Site down ?

Hi Sandyk,
Is Greg's Web Site down or is the link faulty ?
Thanks


sandyK said:
RE JLH PSU Add-on.
As a matter of interest, if they are preceded by 3A regulators such as the MC78T05, and MC78T12 with the Current Limiter section bypassed, and the regulators are doing the current limiting instead , they will work well at +12V 2A and +5V 2A. For best performance at +5V, or even as low as +3.3V, the 10K resistor should be replaced by a Current regulating diode such as the J506 (1.4mA nominal), or a selected FET such as the 2N5484 with Gate and Source tied.
For use with the current limiter section, the main electros should be 2 x 2,200uF in parallel. A 2,200uf 10V low ESR, and a normal 2,200uF is recommended for a neutral sound with Audio.
If used with the Current Limiter section bypassed, a 4,700uF 10V low ESR and a 4,700uF
16V normal type is O.K. too. This is what I am using with a +12v 2A and +5V 2A PSU.
With the CL section bypassed, the voltage drop wil only be several mV due to the copper traces of the PCB tracks, and this will depend on the current being drawn.
At voltages higher than 20V, the CL transistor and the transistor with the 33 ohm emitter resistor should be fitted with small heatsinks.
Further information can be found at Greg Erskine's web site.
Sandyk

Greg's Web Site (Click on Power Supplies.)
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