BOBs and Power Supplies and schematics.

Anything about this unique oscilloscope DIY kit
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LazyWolfe
Posts: 3
Joined: Sun Sep 04, 2016 5:10 pm

BOBs and Power Supplies and schematics.

Post by LazyWolfe »

On the back side of the assembly guide is a chart showing the options for installing Bob2 (or not). This chart references a J2. I assume that J2 is the power connector on one corner of the board?

On the front of the same sheet is a note that reads (in part) "Keep JP2 open if Bob3 is installed." That implies that installing Bob3 is optional. What would cause me to choose to install Bob3 or not?

What about Bob1, Bob4, Bob5? Must these always be installed?

How about all of the other jumpers? e.g. jp4, jp5-9. Are they always jumped? If so, why aren't they just traces on the PCB? If they're optional, what drives the choice to install or not?

Is there a schematic? There are places on the PCB where the solder pads are really close. For instance the inboard ends of R2 and R3. I've checked under a magnifier, and do not see any solder bridge, but my meter shows they are shorted together. It may well be that these resistors are connected. A peek at the schematic would tell me.

I appreciate any help.

russ wolfe
Dave42
Posts: 5
Joined: Mon Aug 08, 2016 3:13 am

Re: BOBs and Power Supplies and schematics.

Post by Dave42 »

You can download a schematic from the bottom of the DSO 068 page
LazyWolfe
Posts: 3
Joined: Sun Sep 04, 2016 5:10 pm

Re: BOBs and Power Supplies and schematics.

Post by LazyWolfe »

Thank you, Dave42, but I'm still wondering about Bob boards and jumpers. The parts list notes that Bob1, 2, and 3 are optional, but I only find detailed information about Bob2 and jP1. Why would I decide not to install Bob 1 or Bob3?
jye1
Posts: 1221
Joined: Wed Feb 20, 2013 4:58 pm

Re: BOBs and Power Supplies and schematics.

Post by jye1 »

I'm sorry for late to reply. Here is brief explanation about the BOB's.

BOB1 is an Uart-USB converter for the serial port. It is not required if the scope is not to connect to PC.

BOB2 is a battery charger with switch. It can be omitted if battery is not used.

BOB3 is a solid state power switch for the scope. It can be omitted if user wants.

BOB4 is a step-up converter to generate 5V power supply. If only USB power, which is 5V, BOB4 can be omitted. But in this case it is better to have D4 shorted to reduce voltage drop.

BOB5 is a negative voltage generator producing -5V. It must be installed since the analog circuits need a negative power source.
LazyWolfe
Posts: 3
Joined: Sun Sep 04, 2016 5:10 pm

Re: BOBs and Power Supplies and schematics.

Post by LazyWolfe »

Thank you, Jye1. Your reply is very helpful. Am I correct in thinking that I must install Bob1 if I want to use JYELab?

Are there any jumpers involved with use of Bob1?

Thanks again,
LazyWolfe
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