I prefer however Cardas eutectic....
Also thanks thanks for the Digikey tip but due to the shipping cost to The Netherlands this is not really an option. I asked for a sample pack at JST.
I have updated the first post with current order status.
It appears I wasn't clear enough with the instructions: if you had already put your name down in the spreadsheet, I need you to email me with the filled-in copy/paste at the bottom of the first post so I can send you a quote and process your order
I've had a few emails too regarding transformer recommendations, and I see tnargs asked above. For those who've already built this, I'd appreciate if you could comment on what you've used.
Thanks
It appears I wasn't clear enough with the instructions: if you had already put your name down in the spreadsheet, I need you to email me with the filled-in copy/paste at the bottom of the first post so I can send you a quote and process your order
I've had a few emails too regarding transformer recommendations, and I see tnargs asked above. For those who've already built this, I'd appreciate if you could comment on what you've used.
Thanks
I used a dual 12Vac. But it was a low pancake style and I think it ended up too close to the PCB.
I want to do a rebuild with a more normal transformer to see if it improves.
I tried a 15Vac transformer, but the regulators get burning hot very quickly.
All the current to the relays goes through the regulators and increases the heat a lot.
With low mains voltage a 12Vac may result in the regulator Vdrop getting a bit too low.
Thus I suggest one uses a dual 13Vac. But no supplier makes them as standard.
I want to do a rebuild with a more normal transformer to see if it improves.
I tried a 15Vac transformer, but the regulators get burning hot very quickly.
All the current to the relays goes through the regulators and increases the heat a lot.
With low mains voltage a 12Vac may result in the regulator Vdrop getting a bit too low.
Thus I suggest one uses a dual 13Vac. But no supplier makes them as standard.
If a remember correctly the full wave rectifier on the circuitboard gives a voltage of 1,4xVac and 0.6xIac after rectification
So the 12V/1A would bring 16 volt, more than enough to compensate for the voltage drop of the regulators, and 600mA, more than enough for the circuit that draw around 200mA.
Please correct me if wrong!
Edit: Googled that...http://www.trans-tronic.co.uk/rectifier/?circuit=Full+wave+bridge+-+capacitor&dc=1&voltage=12¤t=1&calculate=
So the 12V/1A would bring 16 volt, more than enough to compensate for the voltage drop of the regulators, and 600mA, more than enough for the circuit that draw around 200mA.
Please correct me if wrong!
Edit: Googled that...http://www.trans-tronic.co.uk/rectifier/?circuit=Full+wave+bridge+-+capacitor&dc=1&voltage=12¤t=1&calculate=
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Hypex seems to be redesigning their website so 3i found this appnote on online Datasheet - HPR12 - Audio.nl
Max voltage drop is 3 Volt and the "typical application schematic" in the above note suggest 15-40Volt at input
Max voltage drop is 3 Volt and the "typical application schematic" in the above note suggest 15-40Volt at input
Mine runs fine on this, or it would if it did not hummmmmm.
2x12V 6VA Chassis Mounting Mains Transformer | Maplin
2x12V 6VA Chassis Mounting Mains Transformer | Maplin
Looks like very low VA rating is fine then?
As for type, it doesn't matter? EI or toroidal (or r-core I suppose), all okay it seems....
As for voltage, the message seems to be that 2x12Vac is fine (although 2x15 would run slightly hotter and no risk of being close to the 15Vdc minimum recommendation)?
As for type, it doesn't matter? EI or toroidal (or r-core I suppose), all okay it seems....
As for voltage, the message seems to be that 2x12Vac is fine (although 2x15 would run slightly hotter and no risk of being close to the 15Vdc minimum recommendation)?
I think I measured a maximum continuous current of around 140mAdc into the PCB. The measurement was a while ago.
That continuous current would require an AC current rating for the transformer to run at maximum capacity of around 260mA.
To allow the transformer to operate cooler I, as usual, suggest doubling the AC current rating to ~500mA.
dual 13Vac @ 500mA gives a VA rating of 13VA.
That continuous current would require an AC current rating for the transformer to run at maximum capacity of around 260mA.
To allow the transformer to operate cooler I, as usual, suggest doubling the AC current rating to ~500mA.
dual 13Vac @ 500mA gives a VA rating of 13VA.
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