Discussion Overview
The discussion revolves around the considerations for selecting a properly sized power supply for control applications, specifically focusing on devices such as pushbutton lights, alarm horns, and solenoid valves. Participants explore factors like current requirements, inrush currents, and the relationship between AC and DC power supplies.
Discussion Character
- Technical explanation
- Conceptual clarification
- Debate/contested
- Mathematical reasoning
Main Points Raised
- One participant suggests considering both peak inrush current and average holding current when selecting a power supply.
- Another participant recommends making a list of all devices and their current requirements, noting the importance of accounting for large solenoids and motors due to their inrush currents.
- A participant questions whether simply adding up the total current is sufficient for selecting a power supply and seeks clarification on converting inrush current from VA to Amps for a 3-phase system.
- There is a discussion about the distinction between DC and AC power supplies, with a participant providing a formula for calculating Amps from VA for DC supplies and mentioning the complexity of 3-phase AC calculations.
- A participant clarifies their need for a 24VDC power supply fed by 120VAC and emphasizes the importance of selecting the power supply based on total current requirements.
Areas of Agreement / Disagreement
Participants express varying levels of understanding regarding the calculations and considerations for sizing the power supply. There is no consensus on the best approach, and multiple viewpoints on how to handle inrush currents and total current calculations remain evident.
Contextual Notes
Participants have not fully resolved the mathematical steps involved in converting VA to Amps, particularly in the context of 3-phase systems. The discussion also highlights the need for clarity on whether the power supply is DC or AC.
Who May Find This Useful
This discussion may be useful for electrical engineers, technicians, and designers involved in control system design, particularly those working with power supply sizing and current calculations for various devices.