Steve, thanks for the review of the prototype and the suggestions. The serial header does work, it's an "extra" feature I wasn't planning on but gave the unit a backdoor. Press and hold the LEFT & RIGHT buttons to enable bidirectional comms, an LED will flash next to the header. I'll send you the protocol...... I should have mentioned, there _may_ be a 1bit error going from Version 1.00 to V1.01 due to the new version cancelling out a rounding error.......so yours might require a wee re-calibration to get the unit even more accurate.
Toggle Output could be implemented with a firmware update. Use the "Enter" key to toggle output on & off. Add a little indicator on the screen to show when output is on or off. Easy little update which would make this nice.
I'm guessing this product is essentially this: th-cam.com/video/V9l5kc_o_dA/w-d-xo.html But with a more accurate DAC and more expensive reference. Quite a bit of money for that. Guess you are paying for development & calibration. Personally I'm inclined to build the above just because it is such a fun little circuit
Did I miss but what is the current output of this? Looks way too fragile for me to use. I would like to see it with a encoder instead and a back light would be nice too. I would change your charge current if that 400 Ma is in series with those batteries. If they charge in parallel that would be ok.
This is a cheaper version of my PDVS2 (see my online shop) which has the encoder, backlight and a numeric keypad. The output is short circuit protected (21mA max all day long), Min load = 3kohm. Example: At 10Vdc output with 3kohm load = 3.3mA (whilst maintaining output within approx. 10uV) The 400mA is a software setpoint just to protect things if the batteries/hardware goes wrong.....the max charge current is set at 225mA approx. The batteries are in series. I chose the PP3 type as they come with in-battery over and under charge protection, i.e. I have added as much protection as I could in hardware & software given it uses Lithium-Ion batteries. (PS. I will change the text on the 400mA setpoint so it's more intuitive as to what it's for.....or maybe even remove it fom the display!).
Would have been a lot more useful with 0 - 15V range. With 0-10 he lost me as a customer, dealing mostly with automotive 12v . This will be handy for analog device testing, most of which are 12-24V. The way it is, I only see one small niche for this device, ADC testing.
So, this isn't the product for you. Do you blame Ian to not think about you, when he was fulfilling his needs on a voltage source? This is not a product, it's just a way to get a well built and tested piece instead of making it your own, according to the plans and videos, he's provided. Go get those, and make it fit your needs.
Hi, 15Vdc would mean you wouldn't get the 5th dp due to the 20bit DAC (10uV steps 0-10Vdc). Also, two PP3 batteries wouldn't be enough very likely thus major changes required. 0-10Vdc just lands perfectly to the hardware/design. However, I wouldn't rule out a future design for say 0-24Vdc or something like that.
@@IanScottJohnston I completely understand the reasons behind the current range. I figured you'll need more than 20 bit DAC but what I also wondered was, why not use a single battery and DC-DC converter? I'm assuming the battery won't last long enough? Noise? Thank you for your respond and best of luck with your products!
@@111chicane At these small voltages noise and drift is the enemy......DC-DC converters would just cause havoc without going a lot more expensive on the BOM. There are compromizes right, left & centre hence why there aren't too many hand-held precision voltage sources out there......:-)
@@marcus_w0 Mr. Marcus, did someone eat your breakfasts? It wasn't me. I did say in my comment it's not for me, go back and re-read it. I'm not bashing or criticizing the product, I'm suggesting it will get a lot more potential buyers with wider range. Hopefully next time you get to your keyboard, you'll restrain yourself of showing anger. Thank you!
Steve, thanks for the review of the prototype and the suggestions. The serial header does work, it's an "extra" feature I wasn't planning on but gave the unit a backdoor. Press and hold the LEFT & RIGHT buttons to enable bidirectional comms, an LED will flash next to the header. I'll send you the protocol......
I should have mentioned, there _may_ be a 1bit error going from Version 1.00 to V1.01 due to the new version cancelling out a rounding error.......so yours might require a wee re-calibration to get the unit even more accurate.
Thanks Steve...nice to see all my favorite YT guys cooperating!
Great overview Steve! Beautiful build quality @IanScottJohnston :)
Cheers Seon, I spend stupid amounts of time tweaking this and tweaking that to get it how I like it......!
Thanks for the review Steve 👍
Great product! Thanks for pointing it out to us (me)!
Toggle Output could be implemented with a firmware update. Use the "Enter" key to toggle output on & off. Add a little indicator on the screen to show when output is on or off. Easy little update which would make this nice.
Thanks Steve! It looks like a nice voltage reference.
£264 in the UK I feel still out of reach for the ordinary working hobbyist, very nice though for those who can afford one and have a use for it.
There also was amp meter to it would be nice.
Good cheap voltage reference? I use my Fluke multimeter!
Wow ... now I am going to obsess for a few days figuring out how this was made.
как приобрести ?? buy ?
Very nice device. Thanks for the review :-)
I definitely want to purchase one! Is there a link?
Go to www.ianjohnston.com and enter my SHOP and you will see the product there. Use the Notify Me link.
I'm guessing this product is essentially this: th-cam.com/video/V9l5kc_o_dA/w-d-xo.html
But with a more accurate DAC and more expensive reference. Quite a bit of money for that. Guess you are paying for development & calibration. Personally I'm inclined to build the above just because it is such a fun little circuit
Did I miss but what is the current output of this? Looks way too fragile for me to use. I would like to see it with a encoder instead and a back light would be nice too. I would change your charge current if that 400 Ma is in series with those batteries. If they charge in parallel that would be ok.
This is a cheaper version of my PDVS2 (see my online shop) which has the encoder, backlight and a numeric keypad.
The output is short circuit protected (21mA max all day long), Min load = 3kohm. Example: At 10Vdc output with 3kohm load = 3.3mA (whilst maintaining output within approx. 10uV)
The 400mA is a software setpoint just to protect things if the batteries/hardware goes wrong.....the max charge current is set at 225mA approx. The batteries are in series. I chose the PP3 type as they come with in-battery over and under charge protection, i.e. I have added as much protection as I could in hardware & software given it uses Lithium-Ion batteries.
(PS. I will change the text on the 400mA setpoint so it's more intuitive as to what it's for.....or maybe even remove it fom the display!).
@@IanScottJohnston Thanks for the info I will check out your site. Sounds good and that display looks awesome!
need ac v ref,,, pls suggest
Would have been a lot more useful with 0 - 15V range. With 0-10 he lost me as a customer, dealing mostly with automotive 12v . This will be handy for analog device testing, most of which are 12-24V. The way it is, I only see one small niche for this device, ADC testing.
So, this isn't the product for you. Do you blame Ian to not think about you, when he was fulfilling his needs on a voltage source? This is not a product, it's just a way to get a well built and tested piece instead of making it your own, according to the plans and videos, he's provided. Go get those, and make it fit your needs.
Hi, 15Vdc would mean you wouldn't get the 5th dp due to the 20bit DAC (10uV steps 0-10Vdc). Also, two PP3 batteries wouldn't be enough very likely thus major changes required. 0-10Vdc just lands perfectly to the hardware/design. However, I wouldn't rule out a future design for say 0-24Vdc or something like that.
@@IanScottJohnston I completely understand the reasons behind the current range. I figured you'll need more than 20 bit DAC but what I also wondered was, why not use a single battery and DC-DC converter? I'm assuming the battery won't last long enough? Noise?
Thank you for your respond and best of luck with your products!
@@111chicane At these small voltages noise and drift is the enemy......DC-DC converters would just cause havoc without going a lot more expensive on the BOM. There are compromizes right, left & centre hence why there aren't too many hand-held precision voltage sources out there......:-)
@@marcus_w0 Mr. Marcus, did someone eat your breakfasts? It wasn't me.
I did say in my comment it's not for me, go back and re-read it.
I'm not bashing or criticizing the product, I'm suggesting it will get a lot more potential buyers with wider range.
Hopefully next time you get to your keyboard, you'll restrain yourself of showing anger. Thank you!
.