A compact programmable AC power source looks like a simple choice until you get to the spec sheet: some lines need AC output only, others need to switch between AC and DC from the same box, and some need built-in disturbance simulation for pre-compliance testing. Preen's AFV-S and AFV-P series share the same compact form factor and power range, but they answer genuinely different requirements — mixing them up either overpays for capability a line doesn't use, or leaves a test program without a function it actually needs.
What Both Series Share
The AFV-S and AFV-P series are both compact, single-phase programmable AC sources built around the same 0–310V output range and a 2U (600–2500VA) / 4U (5000VA) chassis. Both offer 20 stored memory sets with 4 quick-access shortcuts on a touch screen, useful for production lines that repeat the same handful of test profiles throughout a shift, with a screen lock function to prevent accidental changes mid-run. Standard RS-232 and RS-485 interfaces are included on both, with Ethernet, USB, and (on the AFV-P) GPIB and Analog available as options.
Where They Actually Differ
| Attribute | AFV-S Series | AFV-P Series |
|---|---|---|
| Output modes | AC only | AC and DC, switchable from the same unit |
| Frequency range | 40–500Hz | 15–1000Hz (B variant) or 5–2000Hz (A variant) |
| Power range | 600VA–5000VA | 600VA–6000VA |
| THD | ≤0.3% (110V/220V, 50/60Hz) | ≤0.3% at 5–100Hz, rising to ≤2% at 1501–2000Hz |
| Response time | ≤300µs | ≤300µs |
| Power Line Disturbance simulation | Not included | Built in — supports IEC 61000-4-11, -14, and -28 pre-compliance testing |
| Power factor correction | Standard | Active PFC, raising input power factor to 0.98 |
The two series are built on a related platform, but the AFV-P is the more capable of the two on every axis that matters for compliance-adjacent work: a wider frequency range, a genuine DC output mode, and built-in disturbance simulation the AFV-S doesn't offer at all.
When the AFV-S Is the Right Choice
The AFV-S is sized for straightforward AC-only test lines — home appliance test, LED lighting test, and general manufacturing lines where the requirement is a stable, programmable AC supply across a standard 40–500Hz range, not disturbance simulation or a DC output mode. Where a line genuinely has no use for DC output or PLD simulation, the AFV-S covers the same core power range as the AFV-P without paying for capability that will sit unused.
When the AFV-P Is the Right Choice
AC and DC testing from one instrument. The AFV-P's DC output mode means a single unit covers both AC grid simulation and DC bench testing, rather than needing a separate DC supply alongside the AC source.
Power Line Disturbance pre-compliance testing. Built-in PLD simulation supporting IEC 61000-4-11 (voltage dips, short interruptions, voltage variations), IEC 61000-4-14 (voltage fluctuations), and IEC 61000-4-28 (variation of power frequency) makes the AFV-P the appropriate choice wherever pre-compliance screening against these standards is part of the test plan, ahead of formal certification testing on dedicated compliance equipment.
Wider frequency range. The AFV-P's A-variant models extend to 2000Hz, well beyond the AFV-S's 500Hz ceiling — relevant for equipment tested against non-standard or high-frequency AC conditions.
Choosing Between the AFV-P's A and B Frequency Variants
Within the AFV-P series, the A variant (5–2000Hz) and B variant (15–1000Hz) share identical power and DC output ratings at each power tier — the only difference is frequency range. Specifying the A variant when the test plan never exceeds 1000Hz pays for frequency headroom that goes unused; the B variant covers the same core requirement at a simpler specification wherever the extended range above 1000Hz isn't actually needed.
A Practical Selection Checklist
1. Confirm whether the test plan ever requires a DC output from the same instrument — if yes, only the AFV-P covers this.
2. Check whether IEC 61000-4-11/-14/-28 pre-compliance screening is part of the program — the AFV-S has no PLD simulation capability at all.
3. Confirm the required frequency range against each series' actual ceiling (500Hz for AFV-S; 1000Hz or 2000Hz for AFV-P depending on variant).
4. Size the power tier to the DUT's actual VA requirement, then check whether the standard indoor chassis or a containerized/IP54 option suits the deployment environment.
Finch Electronic Solutions — Melbourne, Australia
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