Look what arrived today:
Could it possibly be...?
Yes!
It's a 10Kg/22lbs behemoth! Now all I need to find is a UK power cable! 
With many, many thanks to James, baldengineer, and Element 14. It was awesome to get selected and this has definitely gone to a good home - I'm looking forward to putting it to good use.
Out of curiosity, and because I've not been able to do such a test yet, I thought I'd start off with a comparison to the PS I have just finished building so I set the two up with a test circuit:
Yaps is driving the circuit on the left, Tenma the one on the left. Both supplies are voltage limited at 5V; the resolution of the Tenma display isn't enough to display current but it's likely to be the same as YAPS at around 10-15mV given both circuits are exactly the same.
It's a 555 timer with 74HC393 binary counter outputting to a number of 74HCnn Logic chips to drive the LEDs. These cycle through digits 1 - 6 as a dice - not visible in the pic as they're a bit bright! It's a circuit that Charles Platt created for his Make: Electronics book and it seemed useful for this purpose. I actually created a video of the circuits running if you're interested.
I just wanted to do a quick comparison of ripple and noise whilst the supplies where driving the circuit. I've clipped the probes to the supplies' outputs and it's not ideal as I've had to use the probes' earth fly lead and connect to short pieces of hook-up wire as I just couldn't get the probes to clip on to the terminals directly. Here's the scope output:
Channels 1 Yellow and 2 Pink are YAPS; 3 Cyan and 4 Green are Tenma. 2 and 4 are measuring AC noise. Measured values, Pk-Pk are:
Channel 1: 0.014V
Channel 3: 0.014V
Channel 2: 0.36mV
Channel 4: 0.46mV
That's as close as makes no difference and over a number of samples, stayed consistent with each other. Given one is SMPS and one is linear, I expect that with different circuits/loads they'd have different characteristics and I'll discover those as I use them.
Top Comments