Shop OBEX P1 Docs P2 Docs Learn Events
SX power supply — Parallax Forums

SX power supply

LightfootLightfoot Posts: 228
edited 2006-02-25 21:24 in General Discussion
What would be the best way to power an SX chip via a bridge rectifier? In addition to the SX chip, I will also power a 74LS04 inverter. The chips will drive a mosfet H bridge. If you want a schematic of what i'm doing say so.

Thanks.

Comments

  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2006-02-25 19:12
    Lightfoot,

    ·· A bridge Rectifier is only one of several parts of a power supply.· Usually the rectifier is preceeded by a step-down transformer (power transformer).· It is followed by filtering capacitors and usually a voltgage regulator.· At this point you can power your SX and TTL logic, but the H-Bridge will most likely require it's own supply.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Chris Savage
    Parallax Tech Support
    csavage@parallax.com
  • LightfootLightfoot Posts: 228
    edited 2006-02-25 19:42
    Yeah, I was thinking since it is a microcontroller driving noisy electric motors you may need to take it further, like adding a choke or applying filter capacitors in a certain way.
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2006-02-25 20:24
    A common thing I see on DC Motors is capacitors on the motor terminals...Usually in the configuration of·three .1 uF·or .01 uF capacitors such that there is one between the two leads, and two more, one from each lead to ground (motor casing).· Now, in some motors I have also seen two chokes coming from the terminals as well going to the H-Bridge.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Chris Savage
    Parallax Tech Support
    csavage@parallax.com
  • LightfootLightfoot Posts: 228
    edited 2006-02-25 21:20
    Thank for the info, I will try the three cap method.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Well well, I'm seeing things, three of them.

    -Stanley Blystone
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2006-02-25 21:24
    That is the most common.· I have seen the added chokes a few times as well including on an R/C tank I am retrofitting.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Chris Savage
    Parallax Tech Support
    csavage@parallax.com
Sign In or Register to comment.