Description
This
Power supply Circuit base on the famous sigma11 circuit. Stable
voltage, ultra-low noise, ultra-low ripple. very suitable for updates
all kind audio device Power supply.
Works voltage: AC115V or AC230V for choose. (we also can custom-make AC100V)
Output voltage: we have following kind for choose. buyer can choose any of the two voltage as the output:
1: DC5V 3.5A
2: DC9V 3.5A
3: DC12V 3.5A
4: DC15V 3A
5: DC18V 2.3A
6: DC19V 2.1A
7: DC20V 2A
8: DC24V 1.8A
9: DC28V 1.5A
10: DC32V 1.5A
(we also can custom-make other voltage. if you need. Please contact us)
Dimensions: 245mm Width X 70mm high X 258mm deep
Transformer : 2pcs 50VA OFC Toroid transformer
Weight: about 6.5kg
DC Head Size: Outer diameter 5.5mm, internal diameter 2.5mm
(it will also compatible with 5.5*2.1mm socket. if you need other Size DC head, Please contact us)
Power Polarity: inner"+" external"-"
Package include: Linear Power supply X 1
0.8M length DC cable X 2pcs
Note: Default is no AC power cable included!!!
Technical highlights
All-discrete topology.
Single-pass, series regulator design.
No
IC (integrated circuits) are used. This allows complete design control
over all operating points and parameters for superior performance.
Low noise, high PSRR
A
constant-current source feeds a zener diode as a stable voltage
reference. A low-pass filter (with a corner frequency of 1.6Hz) prevents
zener noise from being introduced into the error amplifier. This is an
effective yet lower-cost alternative to expensive voltage reference ICs.
The low-pass filter also provides a soft-start characteristic.
The
output noise (unloaded) is less than 13µV at 24VDC output (measured
using a Tangent LNMP (low-noise measurement preamplifier) and a Fluke
187 50000-count DMM in ACmV mode). The output noise is even less when
the output voltage is lower. This is much better than the noise of an IC
regulator based PSU tested under identical conditions.
The error
amplifier is a discrete implementation of an opamp with a high open-loop
gain of 102.5dB. The voltage supply to the error amplifier is isolated
with capacitance multipliers to boost its PSRR (power supply rejection
ratio). This greatly improves the line regulation performance of the
PSU.
A long-tailed pair differential amplifier with current mirror
and constant current source forms the first stage of the error
amplifier. The second stage is the voltage amplification stage (VAS),
also with constant current source load. The 3rd stage is comprised of
the power MOSFET output devices configured as a source follower.
High-current MOSFET pass transistors
Two paralleled high-current, highly reliable MOSFETs (rated at 18A each) serve as the "pass" transistor.
The high current rating provides a very high safety headroom against overcurrent damage.
The
use of paralleled MOSFETs divides the heat dissipation, simplifying
thermal management. Onboard heatsinks can be used which would allow the
this PSU to supply up to 1A continuous (with much higher peak currents).
More sustained currents are possible by using larger, offboard
heatsinks.
The negative temperature coefficient of MOSFETs prevents
damaging thermal-runaway conditions that may plague conventional BJT
devices.
