# What is the regulated output impedance for a given model?

• Knowledge Base ID: 1001
• Category: Hardware

MagnaDC programmable DC power supplies have a regulated output. The regulated voltage mode output impedance can be calculated using Equation 1, while the regulated current mode impedance can be calculated using Equation 2. This regulated output impedance is distinct from the bleed resistance on the output, which will be present in the circuit when the power supply is in standby or turned off. (More information about the bleed resistance is available in Knowledge Base Article 1012).

V_(text(imp))=V_(reg)*(V_(text(rating))/I_(text(rating)))

Equation 1

I_(text(imp))=V_(text(rating))/(I_(text(rating))*I_(reg))

Equation 2

where V_(reg) is the voltage mode load regulation, I_(reg) is the current mode load regulation, V_(text(rating)) is the power supply's full scale voltage rating and I_(text(rating)) is the power supply's full scale current rating.

For example, consider model SL50-80/208. For this model, V_(text(rating)) is 50 Vdc, I_(text(rating)) is 80 Adc, V_(reg) is 0.01% and I_(reg) is 0.04%. Equation 3 provides the calculated output impedance in voltage mode control for this model. Equation 4 provides the calculated output impedance in current mode control for this model.

V_(text(imp))=0.0001*(50/80)

Equation 3

V_(text(imp))=6.25*10^-5 [Ω]

I_(text(imp))=50/(80*0.0004)

Equation 4

I_(text(imp))=1563 [Ω]