Hello, I would like to use the original circuit and while the switch on delay works as expected I get a large spike when switching off of about 100ms because the relay is not switched off fast enough. Do you have a suggestion how to improve here?
Are you powering the board from an AC source (transformer) or are you using a DC rail from elsewhere in the amp?
The relay dropout depends on the supply collapsing quickly. What coil voltage do the two relays use and what supply voltage do you measure on C6?
The relay dropout depends on the supply collapsing quickly. What coil voltage do the two relays use and what supply voltage do you measure on C6?
Using the same PSU for the amp and delay board can be problematic. The relay will not drop out until the supply has fallen considerably. If the board is powered from a separate transformer then the supply fall quickly as C6 is the only source of power.
This is the 12 volt version and shows the AC supply being turned off at 36 seconds.
The rectified DC rail is in green and the relay current in red. The second image is zoomed in to 36 seconds. Notice how quickly the relay current falls because the relay is being fed only from C6.
The last two images show what happens when supplied from a DC supply such as powers the amp. The PSU is turned off at 36 seconds as before but now the rail collapses over 3 seconds. Notice how the relay current simply reduces but the relay will still be engaged. The amp will make its noises during this slow fall in the supply.
(The relay current is shown at the right of the graphs)
And with a DC supply feeding the board.
This is the 12 volt version and shows the AC supply being turned off at 36 seconds.
The rectified DC rail is in green and the relay current in red. The second image is zoomed in to 36 seconds. Notice how quickly the relay current falls because the relay is being fed only from C6.
The last two images show what happens when supplied from a DC supply such as powers the amp. The PSU is turned off at 36 seconds as before but now the rail collapses over 3 seconds. Notice how the relay current simply reduces but the relay will still be engaged. The amp will make its noises during this slow fall in the supply.
(The relay current is shown at the right of the graphs)
And with a DC supply feeding the board.
I'm using the diyaudio dc protection board V3.
Am I correct that there is no ground from it to the star ground in the amp?
Am I correct that there is no ground from it to the star ground in the amp?
Hi ,the part with part number from mouser
relay is obsolete
please tell me a similar relay
Regards
| 653-G5LA-14-CF-DC5 |
please tell me a similar relay
Regards
well i now have 2 questions (because of takis1969 post)
Im getting ready to try to build 2 of the diy speaker protection boards ( 1 for each amp)
First question - in a much earlier comment in this huge thread, "Mooly" states to remove r10 if not using dc protect.
My question is, are the components Q5, Q6, C4, C5, R11, R12 and R13 necessary if no dc protect is to be used?
My electronics background is somewhat limited, but it would appear all those components could be eliminated from my build?
Regarding takis1969 post,
indeed Mouser electronics shows all the OMRON G5LA relays as now obsolete.
Anyone have any ideas as to a replacement?
thanks
Im getting ready to try to build 2 of the diy speaker protection boards ( 1 for each amp)
First question - in a much earlier comment in this huge thread, "Mooly" states to remove r10 if not using dc protect.
My question is, are the components Q5, Q6, C4, C5, R11, R12 and R13 necessary if no dc protect is to be used?
My electronics background is somewhat limited, but it would appear all those components could be eliminated from my build?
Regarding takis1969 post,
indeed Mouser electronics shows all the OMRON G5LA relays as now obsolete.
Anyone have any ideas as to a replacement?
thanks
Farnell/Newark still show 44,000 of some G5LA models in stock, but MOQ=50.
There seem to be similar relays from schrak or Multicomp Pro or Finder available singly.
There seem to be similar relays from schrak or Multicomp Pro or Finder available singly.
I'm certainly no expert, but there must be plenty of alternatives. Look at the key attributes of the G5LA relays that are relevant here (e.g., contact form, contact rating, switching voltage, coil type and operating voltage) and find another brand and/or series that matches (or is damn close to) those found in the G5LA series.
Regards.
Regards.
Is it wise to fuse the DC protector board ?
The toroid feeding it comes straight from the Speaker Turn On Delay board.
The F5 has it's primairy slow blow fuses.
The toroid feeding it comes straight from the Speaker Turn On Delay board.
The F5 has it's primairy slow blow fuses.
You would have to say yes as a general 'cover all' statement.
The peak currents will be quite high and the average much lower given the 220uF reservoir cap so I would suggest something like T315ma as suitable, or you could given the low voltage use an IC protector type device like an ICP-N10 which is 400ma rated. One of those could by 'wire wrapped' in series with the leads of the rectifier eliminating a fuse holder. Another alternative is a very low value fusible resistor.
The peak currents will be quite high and the average much lower given the 220uF reservoir cap so I would suggest something like T315ma as suitable, or you could given the low voltage use an IC protector type device like an ICP-N10 which is 400ma rated. One of those could by 'wire wrapped' in series with the leads of the rectifier eliminating a fuse holder. Another alternative is a very low value fusible resistor.