Friday, December 23, 2011
Thursday, December 22, 2011
BAD power supply.
I'm trying to build a 9V power supply for a camcorder, and after seeing Dave Jones' EEVblog #110, I decided to try using the MC34063 switching power controller.
The circuit I built up on a breadboard produces 9V (well, something like 8.88V really) just fine, but my camera would not turn on! Naturally I went in to diagnostics mode (i.e. I started hunting for the cause by trial and error) and found that I was getting ... well, I'm not entirely sure what to call it. A glitch? Anyway, the voltage would occasionally pulse away from its steady state, anywhere from +/-200mV to over 1V!
After poking around a bit I finally tried hooking the scope up directly to the power output terminals of the BK Precision 1665 power supply I was using to drive my own power supply, and the same glitch was showing up even there, whether there was any load on the terminals or not. Here's the trace on my scope:
It looks absolutely terrible, however I don't think it's the root cause of the camera refusing to power on. I had tested the camera directly connected to the BK and was able to turn it on. It seems like the only remaining candidate is current, though I designed the power supply to be able to handle more than the 560mA that the camera pulls when powered on. More diagnostics are required.
The circuit I built up on a breadboard produces 9V (well, something like 8.88V really) just fine, but my camera would not turn on! Naturally I went in to diagnostics mode (i.e. I started hunting for the cause by trial and error) and found that I was getting ... well, I'm not entirely sure what to call it. A glitch? Anyway, the voltage would occasionally pulse away from its steady state, anywhere from +/-200mV to over 1V!
After poking around a bit I finally tried hooking the scope up directly to the power output terminals of the BK Precision 1665 power supply I was using to drive my own power supply, and the same glitch was showing up even there, whether there was any load on the terminals or not. Here's the trace on my scope:
It looks absolutely terrible, however I don't think it's the root cause of the camera refusing to power on. I had tested the camera directly connected to the BK and was able to turn it on. It seems like the only remaining candidate is current, though I designed the power supply to be able to handle more than the 560mA that the camera pulls when powered on. More diagnostics are required.
Wednesday, December 21, 2011
Jaerb Creators
Just when I thought that the whole mythos surrounding the fictional "Job Creators" had pretty much died out, some twatwaffle whines on PBS Newshour that EPA regulations to keep power companies from poisoning everything will have an undue burden on these fictional job creators. The twatwaffle in question was Scott Segal, director of the Electric Reliability Coordinating Council. Supposedly their mission is to coordinate power generation and transmission across North America but really they just come off looking like lobbyists for power companies.
You didn't even pull the "job creators" card in an even remotely convincing fashion there, guy. Maybe you could dig up some Reagan-era anti-EPA rhetoric that's long since been discredited to along with it.
Who is it that you're actually trying to convince that you'll go out and hire a mess of workers but only if the EPA doesn't tell you to keep your toxins under control? What sort of bullshit blackmail are you trying to pull, here? "You need to let us dump mercury into the atmosphere or we're just going to stop hiring people" (in case it's not patently obvious, not an actual quote, but that's an interpretation).
I must confess I didn't watch the entire interview (or whatever it was supposed to be, despite Jim Lehrer's insistence that opinion, analysis, etc. etc. be readily distinguishable on the NewsHour, it really wasn't clear here), as pulling the "job creator" card pretty much made me not want to hear anything else Segal had to say. Maybe he had some decent points after that, but when you start out regurgitating last year's rhetoric, you don't deserve my ears for the 5 or so minutes you were on.
Phew. Time for some Oedipal Zen.
You didn't even pull the "job creators" card in an even remotely convincing fashion there, guy. Maybe you could dig up some Reagan-era anti-EPA rhetoric that's long since been discredited to along with it.
Who is it that you're actually trying to convince that you'll go out and hire a mess of workers but only if the EPA doesn't tell you to keep your toxins under control? What sort of bullshit blackmail are you trying to pull, here? "You need to let us dump mercury into the atmosphere or we're just going to stop hiring people" (in case it's not patently obvious, not an actual quote, but that's an interpretation).
I must confess I didn't watch the entire interview (or whatever it was supposed to be, despite Jim Lehrer's insistence that opinion, analysis, etc. etc. be readily distinguishable on the NewsHour, it really wasn't clear here), as pulling the "job creator" card pretty much made me not want to hear anything else Segal had to say. Maybe he had some decent points after that, but when you start out regurgitating last year's rhetoric, you don't deserve my ears for the 5 or so minutes you were on.
Phew. Time for some Oedipal Zen.
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