hello everyone,
it’s the second phoenix inverter that shows poor power performance. While powering a 230V 125W soldering iron, the inverter switch in overload mode.
What’s wrong with a resistive load for the phoenix inverter ? 125 W is only 41% of the nominal power of the inverter.
How to fix this issue ?
Thanks for your advices.
Best regards.
Bruno.
Are you sure that the load is purely resistive?
The iron might have a half wave rectifier or be chopping up the sine wave to regulate the irons power rather than using PWM or a regulator.
To be sure, use a scope to look at the sine wave.
If the iron has a high/low setting, set it to high (which might bypass any diode or similar power level hack) and compare the difference
What is the brand and model of iron?
On the other hand - if the soldering iron is “dumb one” (meaning it has no electronic inside), it’s far from simple resistive load. It’s resistance changes by temperature like the one in tungsten bulb (way less resistance when cold i.e. at start), allowing the temperature stabilise at some point.
So no blame to inverter.
No easy solution as far as I see, maybe some big fat resistor with a switch or timer to create naive soft start.
One of the ways to check if my guess is right is to measure the resistance of soldering iron (both ways on the plug to eliminate the effect of some kind of internal diode) when it’s cold - if it’s like 400 - 450 Ohm, then discard my suggestion, as it’s the resistance is close to one for making the nominal power.
Hi RP ! Hi everyone !
Surely not a pure resistive load as I’m unable to measure it with an ohmmeter. So I use incandescent lamps to test at differents power. It’s 100W bulb lamp. I’ve tried several combinations to set power from a few watts to 365 W. Here are the results:
Without load, phoenix in position I, Idc was 0.96 A @ 13.13 V so about 12 W dc consumption.
then efficency is maximum at 90% @ 100 W output power and decrease linearly down to 80% @ 365 W output power and 11.95V and 38 Amps dc input .
So everything looks good and get my apologises for my wrong first test.
Best Regards everyone.
Bruno.