A simple workshop generator m.cz.

Mateusz_konstruktor .... that's a question for me ????, what bulbs are we talking about.
I would like to add that I currently have two more RC PG-23 generators that came to me for repair and the customers have not reported so far.
In the service, the above-mentioned generators in a soap dish housing with a 4.5 volt flat battery worked reliably due to their handyness and simplicity.
73!

@dipole
What bulb did your colleague use, in terms of rated voltage or a specific type?

Bulb usually 12 V with a current of 5-20 mA.

@Mateusz_konstruktor, for example, from manual telephone exchanges. 24V/20mA.

Gismot wrote:

CosteC wrote:

pawlik118 wrote:

A fuse at transformers up to ~2.5VA is not required, from what I remember. Perhaps this is because the very thin wire of the primary winding is not capable of carrying the current that would give off the power that could burn through the insulation between the primary and secondary sides.
e.g. Breve on its products

I know of no such provision.... It would be very strange, besides it assumes that magically nowhere else in the device there will be a failure that can lead to a fire.
The fuse has two roles - protection against fire and protection against shock, of which it protects against shock only in specific cases - because depending on the position of the plug, the fuse may be on the neutral line.

As a curiosity I'll add in the factory equipment of Polish production (metal housing) at 10VA transformers, also was not always used the mains fuse on the primary side of the transformer. The secondary windings of the transformer were always protected by fuses. E.g. ELTRA T8010, T 3015 tuner, ZRK T7010, EQ DIORA FS 042.

On the other hand, the V40.28 power supply in the Meratronik V640 multimeter does not have any fuse. (It is very common for the transformer to fail in them)

In the case of devices in wooden housings or plastic (table radios), the transformer always had a fuse on the primary and secondary sides.

Modern antenna power supply for continuous operation, which does not have any fuses.

Probably has a thermal fuse between the primary and secondary windings of the transformer if the manufacturer used one. I now have a Sencore radio alarm clock from about 15 years ago and there is no trace of a fuse or even a place for a fuse on the PCB. The only protection is the aforementioned thermal fuse if there is one at all in the transformer because the transformer looks Chinese like from Aliexspress. They simply saved money on materials. From what I remember, thermal fuses originally based on bi metal were introduced in radio receivers by Philips as early as the 1930s until almost the end of the era of popularity of electron tubes c
and somewhere until the early 1950s when the first TVs with power supply without a transformer began to appear so they began to replace thermal fuses with normal ones. Po ta to go back to thermal fuses 1970s I have a Philips GA209S Electronic turntable from 74 and also on the primary side only thermal fuse fused with transformer( Philips didn't even specify its type). On the secondary side already a normal 1.25A fuse but only on the secondary side.

There is no thermal fuse, you can see that the windings are bare.

pawlik118 wrote:

There is no thermal fuse, you can see that the windings are bare.

But I have met similar versions where the thermal fuse was. Apparently, it depends on the manufacturer and his vision. One will put it on, because he prefers to blow cold, while others believe that in the event of a short circuit, one end of the winding, which is wound with 0.02 mm wire, will get hot anyway. Then the lead from the winding to the solder tip "does" as a fuse. .