i would consider one of these absolutely essential when repairing any valve and some transistorised equipment, as these limit current automatically, a variac, which some use doesnt, you have to keep your eye on any current meter, i'm currently working on an electronic 'active' variable limiter that gives sharper limiting action, as a bulb limiter will still drop a fair amount of volts when wattage is chosen for a safe current limit, my device will allow nearly full voltage through, so radio operates correctly, but instantly limit current if theres a sudden failure in the radio..ideal for soak testing...
Interesting. It's cool you're into valves. That's an area of electronics I know very little about. Took me some time to recall, but I remember seeing miniture bulbs used in series with stepper motor drivers to limit current. It was fascinating.
Very handy. My repaired 18V lion battery charger causes the lamp to flash every 5 seconds. I'm not sure if it's normal or if there is still a fault with the charger.
not always necessary to replace ALL capacitors, depends where they are in the circuit.... such as a 470 ohm cathode bias resistor in an IF stage, bypassed by a 0.1 uf capacitor....no need to replace that cap as has only a very few volts across it and any leakage wont affect it unless very low resistance, i've never had one go that low, capacitors across mains, coupling to output valve, chassis/aerial/earth dc isolating caps in an ac/dc set, and any directly across ht, if a waxy paper based, definitely yes, as for electrolytics, they might well be still ok, most of my many radios have their originals and still test ok..
Very interesting Jay. Would you recommend that I build one of these for the first power on of the stuff that I am picking up from the dump ? Like the 80's computers and stuff or is it only really useful for the older valve stuff ?
+StigsWorld I wouldn't use one for the power up of a whole computer but if you can isolate the power supply from the rest of the computer then yes a lamp limiter is ideal for first power on as it will allow you to test the psu without danger of damaging anything.
i would consider one of these absolutely essential when repairing any valve and some transistorised equipment, as these limit current automatically, a variac, which some use doesnt, you have to keep your eye on any current meter, i'm currently working on an electronic 'active' variable limiter that gives sharper limiting action, as a bulb limiter will still drop a fair amount of volts when wattage is chosen for a safe current limit, my device will allow nearly full voltage through, so radio operates correctly, but instantly limit current if theres a sudden failure in the radio..ideal for soak testing...
Interesting. It's cool you're into valves. That's an area of electronics I know very little about. Took me some time to recall, but I remember seeing miniture bulbs used in series with stepper motor drivers to limit current. It was fascinating.
+bwack Been into valves for years, I build custom amplifiers for harmonica players from scrap valve radios.
JaysVintageJunk JaysVintageJunk Brilliant !! :)
Interesting! Never seen a bulb used that way - very clever!
Very handy. My repaired 18V lion battery charger causes the lamp to flash every 5 seconds. I'm not sure if it's normal or if there is still a fault with the charger.
Might be a good idea to hook that up to the projector parts for their first power on? :) Clearly explained :o)
Hi, nice video please also add written instructions on building the current limiter in the description to make it easier to understand. Thank you.
what does the in/out switch do? "out" takes the lamp out of the loop?
+David Ammerlaan Yes exactly that
JaysVintageJunk JaysVintageJunk cool
Reforming my arse just replace the caps they are anything between 50-70 years old in these old valve sets.......
not always necessary to replace ALL capacitors, depends where they are in the circuit.... such as a 470 ohm cathode bias resistor in an IF stage, bypassed by a 0.1 uf capacitor....no need to replace that cap as has only a very few volts across it and any leakage wont affect it unless very low resistance, i've never had one go that low, capacitors across mains, coupling to output valve, chassis/aerial/earth dc isolating caps in an ac/dc set, and any directly across ht, if a waxy paper based, definitely yes, as for electrolytics, they might well be still ok, most of my many radios have their originals and still test ok..
Very interesting Jay. Would you recommend that I build one of these for the first power on of the stuff that I am picking up from the dump ? Like the 80's computers and stuff or is it only really useful for the older valve stuff ?
+StigsWorld I wouldn't use one for the power up of a whole computer but if you can isolate the power supply from the rest of the computer then yes a lamp limiter is ideal for first power on as it will allow you to test the psu without danger of damaging anything.