I've ordered a DSO Shell from Banggood, and am concerned about having the right power supply. So a couple questions:
1. I have a 9VDC power adapter, which reads 9.24V under a 100mA load. Is that too high? I see in the schematic that the power input goes through a diode, which will have a forward voltage drop. But I remember seeing somewhere that the Shell is sensitive to having the right supply. So if I were to use an adjustable supply, what voltage would be ideal? Would it be exactly 9V, or would something higher or lower work better?
2. The supply I have is a switching supply. If it proves to be too noisy, what changes can I make to the circuit to reduce noise? Would increasing the value of C10 to 47 uF or 100 uF cause any problems? Would that help filter out swiching noise?
Thanks very much for any suggestions.
Questions about power supply
Re: Questions about power supply
I'm wondering about the same thing.
I bought a multi-voltage regulated power supply ("wall-wart" type adapter) because I didn't want to risk damaging the DSO shell. At the 9V setting it measured 9.13V and as far as it's fine as long as it's below 10V.
Mine is also a 110-240V switching type (that's all I could find) and someone suggested a 2-section filter as described here. It would be nice if something like this could be found ready-made (and in an enclosure) on eBay etc to plug between the 9V power adapter and DSO shell -does anyone know of something like that?
I chose to buy a regulated power supply because I don't want to risk damaging the DSO Shell because of its 10V limitation, and my experience is that the cheap unregulated ones are very unreliable in figuring out the actual voltage they deliver as I don't know how much load the scope will provide and thus lowering the voltage. So it's all guesswork, and I don't want to risk that.
I bought a multi-voltage regulated power supply ("wall-wart" type adapter) because I didn't want to risk damaging the DSO shell. At the 9V setting it measured 9.13V and as far as it's fine as long as it's below 10V.
Mine is also a 110-240V switching type (that's all I could find) and someone suggested a 2-section filter as described here. It would be nice if something like this could be found ready-made (and in an enclosure) on eBay etc to plug between the 9V power adapter and DSO shell -does anyone know of something like that?
I chose to buy a regulated power supply because I don't want to risk damaging the DSO Shell because of its 10V limitation, and my experience is that the cheap unregulated ones are very unreliable in figuring out the actual voltage they deliver as I don't know how much load the scope will provide and thus lowering the voltage. So it's all guesswork, and I don't want to risk that.
Re: Questions about power supply
9.24V is fine. Voltage lower than 10V is considered safe.
Increasing C10 could help reducing noises. Larger C10 shouldn't cause any problem.
Increasing C10 could help reducing noises. Larger C10 shouldn't cause any problem.
Re: Questions about power supply
Which value should C10 have to reduce noise?
If used witha switched power supply, will changing C10 remove the noise or do I still need a filter between the power supply and DSO Shell?
If used witha switched power supply, will changing C10 remove the noise or do I still need a filter between the power supply and DSO Shell?