The TP kits are easy and come with all parts needed, schematics and support. The LCBPS looks like what you need.
Jeroen
Low Current Bipolar Power Supply (LCBPS) - A Regulated CLRC Supply
Jeroen
Low Current Bipolar Power Supply (LCBPS) - A Regulated CLRC Supply
So does anyone have any experiences or words about these? Looks like it might be a good fit for me.
Despite the evil LM317/337
that regulator would be just fine.Note that it is designed for a dual secondary transformer.
How can you tell and what does that mean? Sorry for the noob questions here but I'm still trying to learn a lot of this.
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A dual secondary transformer has 2 separate output windings - it's like 2 transformers in one.
A centre tapped transformer has one output winding but is "tapped" in the middle to split the voltage.
For example:
Dual secondary would be referred to in voltage terms as 22-0, 22-0 whereas a centre tapped would be referred to as 22-0-22. Both transformers can provide either 22 or 44 volts.
See HERE for some pics.
OK, thanks. Looks like they have those dual secondary transformers on that site as well, for $20 for a 15V one, and I don't think that is all that unreasonable. Gives me a starting point for $60 or so and then I can see how it works out.
Now if US customs can get off their butts and send me my record player I'll be happy.
Now if US customs can get off their butts and send me my record player I'll be happy.
A simple +/- 18V Supply
I recently had the need to build just such a supply for a RIAA front end. I used a 35VCT 100 ma toroidal transformer (available from Newark Electronics) connected to a standard fullwave bridge. 120 Hz hum can be minimized by using a C-L-C Pi network instead of just a capacitor. A 4700 uF/20 mH/4700 uF reduced the 120 Hz component to the millivolt level even before the regulators. An LM317/337 pair is used for voltage regulation. All resistors are 1% metal film, and the resistive divider node is bypassed with ~10 uF Ta. The output of the regulators is bypassed with 4700 uF to eliminate any residual noise. The resulting noise level was at the measurement limits of a 6.5 digit voltmeter, or <1 uVRMS. One final note, In their app note, National Semi recommends including a pair of diodes around each regulator to provide input and output protection. 1N4001 diodes or equivalent will work fine. The regulator was built on 2-layer PCB, allowing for a nearly continuous ground plane, and the transformer/regulator is housed in a separate chassis from the preamp itself.
I recently had the need to build just such a supply for a RIAA front end. I used a 35VCT 100 ma toroidal transformer (available from Newark Electronics) connected to a standard fullwave bridge. 120 Hz hum can be minimized by using a C-L-C Pi network instead of just a capacitor. A 4700 uF/20 mH/4700 uF reduced the 120 Hz component to the millivolt level even before the regulators. An LM317/337 pair is used for voltage regulation. All resistors are 1% metal film, and the resistive divider node is bypassed with ~10 uF Ta. The output of the regulators is bypassed with 4700 uF to eliminate any residual noise. The resulting noise level was at the measurement limits of a 6.5 digit voltmeter, or <1 uVRMS. One final note, In their app note, National Semi recommends including a pair of diodes around each regulator to provide input and output protection. 1N4001 diodes or equivalent will work fine. The regulator was built on 2-layer PCB, allowing for a nearly continuous ground plane, and the transformer/regulator is housed in a separate chassis from the preamp itself.
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