Where to find fixed power supplies of: -9V, +9V, and/or -5V

  • Thread starter Thread starter atlbraves49
  • Start date Start date
  • Tags Tags
    Power
Click For Summary

Discussion Overview

The discussion revolves around the availability and suitability of fixed power supplies providing -9V, +9V, and/or -5V outputs. Participants explore various applications, including powering specific circuits and the potential use of bench power supplies versus batteries.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Experimental/applied

Main Points Raised

  • Some participants inquire about the specific application for the power supplies, questioning whether bench supplies or batteries are needed.
  • One participant suggests using bench top power supplies, mentioning options available from Radio Shack and Agilent.
  • Another participant proposes using 9V batteries with snap-on leads, but raises concerns about the circuit design and the specifications of the MCP6001 op-amp.
  • There are discussions about the adequacy of a specific power supply linked in the thread, with varying opinions on its suitability for analog work.
  • Some participants express skepticism about the circuit schematic provided, questioning the appropriateness of the specified voltage supplies for the MCP6001.
  • Participants discuss the implications of a fan in the power supply, with some suggesting it indicates better performance for analog applications due to temperature regulation.
  • There are humorous exchanges about the nature of engineers and the weight of components in the power supply, with references to quiz questions related to power supply design.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the best solution for power supplies, with multiple competing views on the use of bench supplies versus batteries and the validity of the circuit schematic. The discussion remains unresolved regarding the adequacy of the proposed power supply and the specifications of the op-amp.

Contextual Notes

There are unresolved questions about the specifications of the MCP6001 op-amp and the implications of using different voltage supplies. Participants express uncertainty about the circuit design and the reliability of the provided schematic.

  • #31
maybe they've just derated a device to get better performance. how the strain gauge engineers would be privy to that is another matter. I'm also wondering how using this device at low frequencies instead of near 1MHz would affect things. in digital circuits, you certainly have a problem with increased power and heat at higher freq.
 
Engineering news on Phys.org
  • #32
mheslep said:
For the version we've found online apparently, but perhaps there's an upgraded part suggested by this sensor mfn? Certainly +/-9 is not extreme for CMOS op amps in general.

The 5V supply is rather strange, isn't it? I suppose MicroChip, the manufacturer is all about supporting their line of microcontrollers in simple solution applications, where a single +5V supply is all you should.
 
  • #33
Phrak said:
The 5V supply is rather strange, isn't it? I suppose MicroChip, the manufacturer is all about supporting their line of microcontrollers in simple solution applications, where a single +5V supply is all you should.

Why is the 5V strange? I'm guessing you'd just want a stable voltage there, to minimize output drift. 5V regulators are easy to come by.

But I'm thinking pretty much any stable voltage source work there. If the supplies are taken down to 5 volts as was suggested earlier, then one of them could power a 1.25V reference, perhaps an LM337.
 
  • #34
Redbelly98 said:
Why is the 5V strange? I'm guessing you'd just want a stable voltage there, to minimize output drift. 5V regulators are easy to come by.

So I went to Texas Instruments web pages and did a parametric search on Standard Linear Amplifiers. The 36 out of 221 listed had a V_s_max of 5.5 volts or less. Not a lot, but more prevalent than I had thought.

The Microchip web pages were revealing. Revealing what, I'm not sure :smile:. 69 out of 72 of their operational amplifiers listed a V_s_max of 6 volts or less.

V_s_max, by the way, is the maximum Vdd to Vss operating voltage.

The flex-thing schematic is wrong. I'm repeating myself. The 18 volts is far above the chip spec. of 5.5V. 18 volts will likely smoke it.


The MC6001 is to be used with a single +5V to ground supply. 4.5 Volts of batteries is OK.

http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en010433"
 
Last edited by a moderator:

Similar threads

Sizing an Isolation Transformer for a DC Power Supply
  • · Replies 8 ·
Replies
8
Views
3K
Manually charging batteries
  • · Replies 11 ·
Replies
11
Views
2K
Power managment for this circuit supplying power to my pump load
  • · Replies 21 ·
Replies
21
Views
2K
Can a common 9V power supply be used as a -9V supply?
  • · Replies 2 ·
Replies
2
Views
6K
DC-DC conv. Ripple affecting Speech Recognition - Capacitance multiplier
  • · Replies 22 ·
Replies
22
Views
2K
Can power supplies/adapters be used to clean up dirty generator power?
  • · Replies 61 ·
3
Replies
61
Views
10K
Share a power supply between two devices
  • · Replies 8 ·
Replies
8
Views
3K
Calculating the filter capacitor for a power supply
  • · Replies 2 ·
Replies
2
Views
3K
AC-DC Power Supply Modules: Non-Isolated Topology
  • · Replies 11 ·
Replies
11
Views
3K
How do I properly connect a bench power supply to a pulse generator for testing?
  • · Replies 19 ·
Replies
19
Views
3K