[Sunrivers]

16V 2F ok?​

 

[Kentajalli]

As long as it can take 9V, it is OK.
but 16V is a little wasted on us in this case.
if that assembly fits inside, wonderful!

 

[Sunrivers]

If I use four 2.7V 25F supercapacitors in series, will I get 10.8V 6F? Is this enough?

 

[Sunrivers]

Each size is 16x26 mm.

 

[Kentajalli]

Each size is 16x26 mm.

Won't fit inside, 16mm is too thick.
3 would be enough if you can find a stabalized 8V powersupply (not charger).
Again, please look at posts above regarding getting the right size caps.

 

[Sunrivers]

Thanks.

 

[ecapsretliab]

Any thoughts on just replacing the battery with an LT3045 regulator set to 8.2V?


Then just hooking it up to a 9V LPS via a DC jack mod?

Would this be a viable option?

 

[Kentajalli]

Any thoughts on just replacing the battery with an LT3045 regulator set to 8.2V?


Then just hooking it up to a 9V LPS via a DC jack mod?

Would this be a viable option?

Yes it would, but still needs some storage afterwards, in form of large capacitors, both for stable operation of device and transient current draw by Mojo.
I would put the regulator outside the device to make sure there would be no MRI and allow cooling.
If I am not mistaken the device requires 1.2V minimum to operate, so 9V supply won't work, needs 9.4V min. or more.
This voltage difffrence multiplied by supply current will be given off as heat.
Say 10V input, 8.2V output at 200mA means 360mW heat generation.
The pictured item is unlikely to be able to supply the needed currents, too small.

 

[ecapsretliab]

Yes it would, but still needs some storage afterwards, in form of large capacitors, both for stable operation of device and transient current draw by Mojo.
I would put the regulator outside the device to make sure there would be no MRI and allow cooling.
If I am not mistaken the device requires 1.2V minimum to operate, so 9V supply won't work, needs 9.4V min. or more.
This voltage difffrence multiplied by supply current will be given off as heat.
Say 10V input, 8.2V output at 200mA means 360mW heat generation.
The pictured item is unlikely to be able to supply the needed currents, too small.

Interesting, thanks for that. I think I'll eventually go with the SC option outlined earlier.

May I ask, you mention...

"Better still, find a 9V LPS (easier to find), but add one diode in series, and a large capacitor or super-capacitor inside MOJO"

Could you please explain the "diode" part. I'm not sure of the parameters.

Thanks.

 

[Kentajalli]

Interesting, thanks for that. I think I'll eventually go with the SC option outlined earlier.

May I ask, you mention...


Could you please explain the "diode" part. I'm not sure of the parameters.

Thanks.

Since using a non standard Powersupply , a bit of protection against reverse wiring (polarity) is wise.
secondly, finding a stabalized 8.2V is difficult , but 9V is easy.
By using a diode you achieve both safety against reverse polarity and the 9V drops to 8.25V !
the extra 0.75V is diodes forward bias voltage.
If you are going for super-capacitors , make sure your Powersupply is current limited, or at switch on, you either pop the diode or the Powersupply !

 

[ecapsretliab]

Since using a non standard Powersupply , a bit of protection against reverse wiring is wise.
secondly, finding a stabalized 8.2V is difficult , but 9V is easy.
By using a diode you achieve both safety against reverse polarity and the 9V drops to 8.25V !
the extra 0.75V is diodes forward bias voltage

I see, so a 1A 1000V on the + wire would be ok? I've never worked with diodes before.

Cheers.

 

[Kentajalli]

I see, so a 1A 1000V on the + wire would be ok? I've never worked with diodes before.

Cheers.

Yep.
it will subtract 0.75V from supply.
if 9V, then you get 8.25V at other end, regardless of current.

 

[ecapsretliab]

Yep.
it will subtract 0.75V from supply.
if 9V, then you get 8.25V at other end, regardless of current.

Cheers, when I finally get around to it, I'll post my results.

 

[Tjj226 Angel]

Why are you guys using super capacitors for this? Isn't the dac internally regulated? If so, the last regulator in the chain WILL be noisier than a decent quality lithium ion battery.

 

[Kentajalli]

Why are you guys using super capacitors for this? Isn't the dac internally regulated? If so, the last regulator in the chain WILL be noisier than a decent quality lithium ion battery.

I am with you on this.
In principle, I am against not using batteries.
However . . .
Many have decided to use their Mojo as desktop DACs - to this end, they like to hook it up to a power supply all the time.
So they ask, and I answer best I can.
Others have tried different methods, look above.