Hi,
PCBs are in transit, so I'm going through ordering parts needed for the kit now..
I am finding 15VAC 1000mA PSUs are not easy to come by, will 16VAC, like this one work ok? -> http://www.jameco.com/webapp/wcs/stores ... _100108_-1
If not, any leads on where to find a 15VAC 1000mA? I'm in the US.
Also, is there anything recommended in the current BOM that should be replaced? I am taking KlangGenerators advice and will be ordering these Cherry Switches -> http://www.mouser.com/ProductDetail/CHE ... fZ%2fFDjs=
Will be ordering sockets for all IC's as well. I read somewhere on here which ones are needed - I'll have to find that.
This is my first real DIY (buy components separate) build, so apologies for these perhaps basic questions. Any help would be much appreciated!
Thank you.
16VAC 1000mA PSU compatible with NAVA?
16VAC is good as 15CAC and 17V. I think that 18VAC will god as well. Find transformer which has secondary 16VAC. On primnary put some fuse (fast one, 1A is enough), put this into some box and -> will be much better power supply than you can buy 
Hi,
That 16VAC wall wart will do fine. Before I made an internal power supply I used a 16V AC wall wart from an old router. Works like a charm.
That 16VAC wall wart will do fine. Before I made an internal power supply I used a 16V AC wall wart from an old router. Works like a charm.
Thank you for the response. So just making sure, the 16VAC posted will work fine with the current BOM? I don't need to altar anything from PSU components/parts included in the BOM, do I?jeroenbvo wrote:Hi,
That 16VAC wall wart will do fine. Before I made an internal power supply I used a 16V AC wall wart from an old router. Works like a charm.
Thanks again.
The more AC voltage you have the more heat is produced with the linear voltage regulators, i think in the nava they produce +-15V with the big linear regulators, the ones with the heatsinks attached.
Now the more heat you will get the more it derates, so sticking with the recommended 15V ac is generally the best approach, you can of course use also put 16 vac or more into your nava, but at some point those regulators will simply melt.
P=U*I
where U is the voltage difference between input voltage, lets say 15V * root 2, cause we need the peak voltage, and then subtract the 15V output from it, times the current flowing thru it.
Around 1 W should be hot but ok in the regulator.
Now the more heat you will get the more it derates, so sticking with the recommended 15V ac is generally the best approach, you can of course use also put 16 vac or more into your nava, but at some point those regulators will simply melt.
P=U*I
where U is the voltage difference between input voltage, lets say 15V * root 2, cause we need the peak voltage, and then subtract the 15V output from it, times the current flowing thru it.
Around 1 W should be hot but ok in the regulator.
Thank you for the reply. So, I just want to confirm that if I use the 16VAC PSU I posted above, I should more or less be ok without modifying whats in the BOM? Apologies as my electronics knowledge is very beginner at the moment.mex wrote:The more AC voltage you have the more heat is produced with the linear voltage regulators, i think in the nava they produce +-15V with the big linear regulators, the ones with the heatsinks attached.
Now the more heat you will get the more it derates, so sticking with the recommended 15V ac is generally the best approach, you can of course use also put 16 vac or more into your nava, but at some point those regulators will simply melt.
P=U*I
where U is the voltage difference between input voltage, lets say 15V * root 2, cause we need the peak voltage, and then subtract the 15V output from it, times the current flowing thru it.
Around 1 W should be hot but ok in the regulator.
The drop out voltage of these regulators is normally around 2V. Meaning to keep the regulator running you must have a difference of 2V between input and output. So it needs minimum of 17V DC.
Feeding it with a 15V AC source, where after rectification, but before the 7815 you'll have 21.2V DC unloaded, so perfect. With 16V AC you end up with 22.6V DC. Not an issue considering generally the max input for these regulators is around 35V.
You need to heat sink them though, whether or not you use 15 or 16 V AC. Otherwise they can become too hot and the internal thermal shut off will kick in. They won't melt, that only happened with the old ones produced before the 90's.
Again, no issue using the 16V AC adapter. If you look in the project pages, E-licktronic is also suggesting either one of the two.
Feeding it with a 15V AC source, where after rectification, but before the 7815 you'll have 21.2V DC unloaded, so perfect. With 16V AC you end up with 22.6V DC. Not an issue considering generally the max input for these regulators is around 35V.
You need to heat sink them though, whether or not you use 15 or 16 V AC. Otherwise they can become too hot and the internal thermal shut off will kick in. They won't melt, that only happened with the old ones produced before the 90's.
Again, no issue using the 16V AC adapter. If you look in the project pages, E-licktronic is also suggesting either one of the two.
Cheers, thank you for the help!jeroenbvo wrote:The drop out voltage of these regulators is normally around 2V. Meaning to keep the regulator running you must have a difference of 2V between input and output. So it needs minimum of 17V DC.
Feeding it with a 15V AC source, where after rectification, but before the 7815 you'll have 21.2V DC unloaded, so perfect. With 16V AC you end up with 22.6V DC. Not an issue considering generally the max input for these regulators is around 35V.
You need to heat sink them though, whether or not you use 15 or 16 V AC. Otherwise they can become too hot and the internal thermal shut off will kick in. They won't melt, that only happened with the old ones produced before the 90's.
Again, no issue using the 16V AC adapter. If you look in the project pages, E-licktronic is also suggesting either one of the two.