power supply - How to test the maximum secondary current of a step down transformer?

I got a small step down transformer from my local market which has a total of 6 individually isolated winding in it (1 primary of 230V and 5 different secondary wingding with 5 different voltage).

My question is that how can I find out the maximum output current for the secondary winding? I was told generally these used to be made for "Small Sound Systems". As this from a local market it has no datasheet. Transformer weights about 500 grams and looks well made. The dimensions of the transformer are near about 6cm X 3cm X 5cm and all the secondary wires are less than 1mm in dia.

This is my first question on stackexchange. Thanks in advance for all help and suggestions!

The winding voltages and resistance measured are as follows:

1. Primary Winding (Red thick wire) 230V with a resistance of 72.6 ohms


2. Blue Wire 8.8V with a resistance of 1.4 ohms



3. Yellow Wire 11.1V with a resistance of 2.0 ohms


4. Green Wire 12.8V with a resistance of 2.7 ohms


5. White Wire 23.1V with a resistance of 9.1 ohms


6. Red wire 3.7V with a resistance of 1.8 ohms

These are all the output voltages when the transformer is given 230VAC as input.

I tried measuring the maximum output current by a short circuit test (Using some high watt ceramic resistance in series with my DMM in amp mode).But unfortunately the DMM is not showing anything, I double checked my DMM for a blown fuse inside but it was working properly when I tested a DC load.

I want to use this transormer for building up a variable power supply circuit, but without getting sure of it's maximum output current of the secondary windings, I can't proceed further.I am not that much experienced of power electronics hence can't figure out what to do next.

Here are some pictures of it Thanks again for helping me,

Best Regards,

Robbin