Search found 15160 matches

by Nick
Mon Jun 05, 2023 8:26 pm
Forum: Beginners
Topic: NFB capacitor
Replies: 18
Views: 2155

Re: NFB capacitor

I would guess in the absence of of a cap on the input the resistance looking into the pot from the LTP base is whats causing the change. What I would suggest trying is a resistor to ground on the front of the amp so the resistance to ground on the +ve LPT base is the same as the resistance seen to t...
by Nick
Mon Jun 05, 2023 5:26 pm
Forum: Beginners
Topic: NFB capacitor
Replies: 18
Views: 2155

Re: NFB capacitor

BTW, the ones I found are only 22uf 50v, I use 100uf 50v for my amps, but the ones I will send should be ok to try.
by Nick
Mon Jun 05, 2023 4:50 pm
Forum: Beginners
Topic: NFB capacitor
Replies: 18
Views: 2155

Re: NFB capacitor

Just though, if you have changed the feedback resistor I would argue that you should also change the resistor to ground for the input side of the LTP as well to match, so they are both seeing the same DC conditions to ground (or virtual ground in the case of the feedback side) on their bases. But al...
by Nick
Mon Jun 05, 2023 4:18 pm
Forum: Beginners
Topic: NFB capacitor
Replies: 18
Views: 2155

Re: NFB capacitor

If you are interested I think I have some of the bipolar caps I use. I can put four of them in the post to you if you want to give them a try.
by Nick
Sun Jun 04, 2023 11:07 am
Forum: Assorted Stuff
Topic: Anyone here understand tuning PID controllers?
Replies: 14
Views: 354

Re: Anyone here understand tuning PID controllers?

Yep, it talks about setting the cycle time to 20 seconds with a relay output to protect the contacts, I think the same will apply to your bulb's (and state of mind).
by Nick
Sun Jun 04, 2023 10:37 am
Forum: Assorted Stuff
Topic: Anyone here understand tuning PID controllers?
Replies: 14
Views: 354

Re: Anyone here understand tuning PID controllers?

Looking at the manual online, looks like setting a longer "Control Cycle Time" might slow the flashing.
by Nick
Sat Jun 03, 2023 11:13 pm
Forum: Assorted Stuff
Topic: Anyone here understand tuning PID controllers?
Replies: 14
Views: 354

Re: Anyone here understand tuning PID controllers?

The worst thing we had to control was pressure of argon in a 3m * 5m * 2m pressure vessel. This was on the plattens of a hydraulic press heated up to 600C (the platterns had three racks full of pid controllers and thyristor power controllers controlling the individual zones). The input valve was tin...
by Nick
Sat Jun 03, 2023 10:58 pm
Forum: Assorted Stuff
Topic: Anyone here understand tuning PID controllers?
Replies: 14
Views: 354

Re: Anyone here understand tuning PID controllers?

The TD4 controller has a "learn" mode that auto-tunes That will be using one of the algorithms I mentioned. I would let it try that and use the parameters it finds as a starting point. It will probably turn the output on and let it ramp up way past the setpoint, so make sure there is noth...
by Nick
Sat Jun 03, 2023 8:00 pm
Forum: Assorted Stuff
Topic: Anyone here understand tuning PID controllers?
Replies: 14
Views: 354

Re: Anyone here understand tuning PID controllers?

Also, given that I assume you only have a on off output (I finally read the rest of your post), 50% output is going to look like what you describe. Maybe work using more I than P in those situations, but that will tend to make the output waver around the setpoint. I would think about using some meta...
by Nick
Sat Jun 03, 2023 7:52 pm
Forum: Assorted Stuff
Topic: Anyone here understand tuning PID controllers?
Replies: 14
Views: 354

Re: Anyone here understand tuning PID controllers?

Turn I and D to 0. turn up P until it just starts to oscillate. back P down 25%. Then turn I up until it starts to overshoot. Turn down 20%. Turn up D just so you feel you are getting your moneys worth, but in my experience unless you have a fast system with a rapidly moving setpoint it won;t matter...
by Nick
Tue May 30, 2023 10:26 pm
Forum: Assorted Stuff
Topic: Help with what speakers to take to the WAM show.
Replies: 14
Views: 697

Re: Help with what speakers to take to the WAM show.

Unrelated loudspeaker question that occurred to me. has anyone taken a electrostatic bass panel and put it inside a sealed box or a port loaded one?
by Nick
Sun May 28, 2023 4:21 pm
Forum: Assorted Stuff
Topic: Interesting (non musical) YouTube videos.
Replies: 306
Views: 60227

Re: Interesting (non musical) YouTube videos.

Didn't he call his butler "Scrotum" because he was his wrinkled old retainer? "Scrotum, the wrinkled retainer" was the exact quote if I remember. As always the original radio and then LP was IMHO far better than the film as to me the joy of it was its (his) use of language. That...
by Nick
Sun May 28, 2023 1:48 pm
Forum: Assorted Stuff
Topic: Interesting (non musical) YouTube videos.
Replies: 306
Views: 60227

Re: Interesting (non musical) YouTube videos.

Silly bugger's got spiked running shoes on.
by Nick
Sun May 28, 2023 12:54 pm
Forum: Computer Audio
Topic: Is streaming profitable......
Replies: 11
Views: 1182

Re: Is streaming profitable......

I'm perplexed how remastering a vinyl copy of one of your albums indicates thumbs up for streaming your albums ? So would I, but given that you replied to a post (I can only assume the previous post to yours was what you were replying to, given the lack of quotes in your post) that was talking abou...