Hi Cristi,
My speaker protection circuit and V2 TA2022 pcb has arrived.
Can you answer my questions in post #167?
http://www.diyaudio.com/forums/showthread.php?postid=1799200#post1799200
I'm wondering how small a transformer I can get away with for the speaker protection module.
cheers,
col.
My speaker protection circuit and V2 TA2022 pcb has arrived.
Can you answer my questions in post #167?
http://www.diyaudio.com/forums/showthread.php?postid=1799200#post1799200
I'm wondering how small a transformer I can get away with for the speaker protection module.
cheers,
col.
COL,
i will copy-paste the answer from post #174
for the speaker protection circuit, the minimum transformer which can be used need to provide at least 9V AC, which after rectifier and filter will be 12V DC. the required current is 50mA, so the transformer power can be less than 1W.
if different voltage value is available, for example 16V AC, this can be also used, but need to change the resistor R4 with different value which need to be recalculated dependin on the board DC voltage and relay DC resistance (ussualy 270 Ohms). if the voltage is higher than 16V AC, the C2 capacitor need to be canged with a hgher voltage one.
the board also can be used with DC power supply, just connect negative voltage to the pin GND, positive voltage to the pin +Vcc and AC1 for AC detect.
the soft start circuit uses its own transformer, no need other transformer to power this circuit. in addition there is "remote" pin option, which allows to remote connect disconnect the circuit using a controller board (comming soon) or a logic level signal.
the answer for your second post is no, since you need symetrical voltage, +-15V and spk. protection circuit use single supply voltage, have only the positive one, doesn't have the negative one.
i will copy-paste the answer from post #174
for the speaker protection circuit, the minimum transformer which can be used need to provide at least 9V AC, which after rectifier and filter will be 12V DC. the required current is 50mA, so the transformer power can be less than 1W.
if different voltage value is available, for example 16V AC, this can be also used, but need to change the resistor R4 with different value which need to be recalculated dependin on the board DC voltage and relay DC resistance (ussualy 270 Ohms). if the voltage is higher than 16V AC, the C2 capacitor need to be canged with a hgher voltage one.
the board also can be used with DC power supply, just connect negative voltage to the pin GND, positive voltage to the pin +Vcc and AC1 for AC detect.
the soft start circuit uses its own transformer, no need other transformer to power this circuit. in addition there is "remote" pin option, which allows to remote connect disconnect the circuit using a controller board (comming soon) or a logic level signal.
the answer for your second post is no, since you need symetrical voltage, +-15V and spk. protection circuit use single supply voltage, have only the positive one, doesn't have the negative one.
thanks for that, overlooked post #174.
I like the idea of the soft start remote. My system is tri-amped, at the moment when I turn it on there is too many power buttons to switch on/off. Especially, seeing I use independent mute on each amp. Turning my system on is like powering up the space shuttle. I'm getting a bit bored with the start up sequence.
col.
I like the idea of the soft start remote. My system is tri-amped, at the moment when I turn it on there is too many power buttons to switch on/off. Especially, seeing I use independent mute on each amp. Turning my system on is like powering up the space shuttle. I'm getting a bit bored with the start up sequence.
col.
hoxuanduc said:
Hi
all TA2022 and Ta3020 boards which i have at the moment has heatsink.
the capacitors size are: for TA2022 board default 10.000uF/50V on request i can put 10.000uF/63V, or 12.000uF/63V
for TA3020 V2 board 12.000uF 63V, TA3020 V3 has smaller caps, just 470 or 1000 uF since the board is also very small.
other capacitors values available on request, including external power supplies with up to 108.000 uF !!!
spk gnd on speaker protection module
Hi Cristi,
Another stupid question. The speaker protection module only has one speaker gnd terminal. How do I connect both the output gnds from the TA2022 module and the gnd going to the speaker binding posts. Do I just bundle them all together?
Also, I want to power it with 15v DC. What value resistor does R4 need and where do I connect AC1?
col.
Hi Cristi,
Another stupid question. The speaker protection module only has one speaker gnd terminal. How do I connect both the output gnds from the TA2022 module and the gnd going to the speaker binding posts. Do I just bundle them all together?
Also, I want to power it with 15v DC. What value resistor does R4 need and where do I connect AC1?
col.
re speaker protection
Col,
The protection is done using a upc1237 IC. Get the data sheet from the internet. You can also download the Omron G2R relay specs. Christi can send you the schematic. However it is similar to the generic one on the data sheet. The module is set up for operation from an AC12v supply.
On the data sheet for the upc1237 it shows how you adjust it for different voltages.
Looking at the data sheet, R4 is set up to give 3.4V at the IC. The max allowable voltage is 8V. The resistor selection graph suggests that about 5k might be right. 4.7K is used so it should be OK as is without changing anything.
However since the protection module is set up to run from AC12V it can handle DC easily.
I am running mine from DC 12V fed to the AC input terminals (need to get the polarity right so that the AC sense is correctly triggered on). Thus the voltage at the relay is reduced by 0.6V - ie 11.4V which is fine (it works). The AC sense will also be OK as the 15k resistor used in the module is OK for up to 25V AC according to the datasheet. (Obviously the AC sense wont shut it down if you are using DC from a separate power supply, but it needs to be triggered to allow it to run).
Cant answer earth issue but Id try just connecting them together. (different connection methods probably only affect RF emissions - though I am not qualified to comment here).
Cheers
Derick
Col,
The protection is done using a upc1237 IC. Get the data sheet from the internet. You can also download the Omron G2R relay specs. Christi can send you the schematic. However it is similar to the generic one on the data sheet. The module is set up for operation from an AC12v supply.
On the data sheet for the upc1237 it shows how you adjust it for different voltages.
Looking at the data sheet, R4 is set up to give 3.4V at the IC. The max allowable voltage is 8V. The resistor selection graph suggests that about 5k might be right. 4.7K is used so it should be OK as is without changing anything.
However since the protection module is set up to run from AC12V it can handle DC easily.
I am running mine from DC 12V fed to the AC input terminals (need to get the polarity right so that the AC sense is correctly triggered on). Thus the voltage at the relay is reduced by 0.6V - ie 11.4V which is fine (it works). The AC sense will also be OK as the 15k resistor used in the module is OK for up to 25V AC according to the datasheet. (Obviously the AC sense wont shut it down if you are using DC from a separate power supply, but it needs to be triggered to allow it to run).
Cant answer earth issue but Id try just connecting them together. (different connection methods probably only affect RF emissions - though I am not qualified to comment here).
Cheers
Derick
I just arrrived back afeter 1 may holiday.
thx derick for answer, i would like to add that the GND doesn't draw current and is not level sensitive, is used just for GND reference and can be connected virtually at any point in the circuit, that's why is single connection. is prefferable to connect at the star point, and not to connect together the gnd outputs. for example for TA3020 amplifier module, should be connected at the pin 4 main connector, which is the power GND.
for killerbobjr.
i signed-up for the google checkout, but i only can pay, not receive money. for other forms of payment i didn't get the aproval yet. some of them ask useless informations and need to wait and wait and wait. for others is too suspicious that i'm other nationality than the country where i am right now and i can't get the account for this reason. i applied for 2checkout as well, and i have to wait the aproval. anyway, the rates are higher than paypapal and conditions seems similar. i will post from their website: "Basic transaction fees are as advertised.
Signup/Account Establishment Fee:
There is a one-time set-up fee of $49.
Transaction Fees:
2CO applies a 5.5% commission on each transaction, plus a $0.45 charge per transaction.
Additional Penalties and Fees:
If you elect to pay the sign up fee via the check or PayPal method and we do not receive the funds, a manual adjustment can be made for the $49.00 plus a $25.00 manual processing fee from the current balance on the account."
anyway, i'm looking forward and right now i'm speaking with some guys to add them as distribuitors in few major countries and will be more convenient for everybody.
thx derick for answer, i would like to add that the GND doesn't draw current and is not level sensitive, is used just for GND reference and can be connected virtually at any point in the circuit, that's why is single connection. is prefferable to connect at the star point, and not to connect together the gnd outputs. for example for TA3020 amplifier module, should be connected at the pin 4 main connector, which is the power GND.
for killerbobjr.
i signed-up for the google checkout, but i only can pay, not receive money. for other forms of payment i didn't get the aproval yet. some of them ask useless informations and need to wait and wait and wait. for others is too suspicious that i'm other nationality than the country where i am right now and i can't get the account for this reason. i applied for 2checkout as well, and i have to wait the aproval. anyway, the rates are higher than paypapal and conditions seems similar. i will post from their website: "Basic transaction fees are as advertised.
Signup/Account Establishment Fee:
There is a one-time set-up fee of $49.
Transaction Fees:
2CO applies a 5.5% commission on each transaction, plus a $0.45 charge per transaction.
Additional Penalties and Fees:
If you elect to pay the sign up fee via the check or PayPal method and we do not receive the funds, a manual adjustment can be made for the $49.00 plus a $25.00 manual processing fee from the current balance on the account."
anyway, i'm looking forward and right now i'm speaking with some guys to add them as distribuitors in few major countries and will be more convenient for everybody.
Thanks dgm and cnx,
I have got the speaker protection board hooked up to a ESP P05b (15v DC) which is being supplied from the main 22-0-22v AC 225VA transformer that is powering the TA2022 board, it seems to be working fine, this way I don't have to add another transformer.
The P05b regulators are having to drop around 7v which should be fine as long as I heatsink them properly. I need to keep it at 15v because I'm going to be powering a ESP P87a balanced receiver board.
I haven't connected the TA2022 or any speakers yet but testing with my multimeter the speaker protection board seems to be functioning.
Hoping to get some time to finish this amp over the next few days or maybe the weekend. Will put up some photos on my website.
cheers,
col.
I have got the speaker protection board hooked up to a ESP P05b (15v DC) which is being supplied from the main 22-0-22v AC 225VA transformer that is powering the TA2022 board, it seems to be working fine, this way I don't have to add another transformer.
The P05b regulators are having to drop around 7v which should be fine as long as I heatsink them properly. I need to keep it at 15v because I'm going to be powering a ESP P87a balanced receiver board.
I haven't connected the TA2022 or any speakers yet but testing with my multimeter the speaker protection board seems to be functioning.
Hoping to get some time to finish this amp over the next few days or maybe the weekend. Will put up some photos on my website.
cheers,
col.
Hi Cristy,
could you please tell me, how could I trim trimmers between diodes from SAP15 on LM4702?
Now I have 70mV between D pin from PNP to D pin from NPN in both channels.
What is the best value?
I am using amplifier for ribbons and I have some DC offset- where can I change It closer to zero?
Thank you,
Robert
could you please tell me, how could I trim trimmers between diodes from SAP15 on LM4702?
Now I have 70mV between D pin from PNP to D pin from NPN in both channels.
What is the best value?
I am using amplifier for ribbons and I have some DC offset- where can I change It closer to zero?
Thank you,
Robert
Hi Robert
what do you mean how can you trim the trimmers ? i simply use a small screwdriver to do this. they are multiturns, so you need to rotate them carefully.
since the transistors have compensating diodes internally, the voltage between D pin of the transistors is small, less than 100mV. the recommended current is 2.5mA and the idle current thru transistors is 40mA. to adjust this current, you need to measure between S pins of the transitors a voltage value of 17.6 mV corresponding at 40mA idle current.
the DC offset voltage is given by the LM4702 IC, they state in the datasheet that the value can be between 10 to 35mV. if this value is too high for you, you may try to reduce this by externally bias the noninverting input pin of the IC with a high value resistor (about 1MOhm) connected to a trimmer which can provide the desired voltage to cancell the DC offset. there are also more complex methods to cancell the DC offset, but this involves modifications.
note that LME49810 has the DC offset about 10 times smaller.
what do you mean how can you trim the trimmers ? i simply use a small screwdriver to do this. they are multiturns, so you need to rotate them carefully.
since the transistors have compensating diodes internally, the voltage between D pin of the transistors is small, less than 100mV. the recommended current is 2.5mA and the idle current thru transistors is 40mA. to adjust this current, you need to measure between S pins of the transitors a voltage value of 17.6 mV corresponding at 40mA idle current.
the DC offset voltage is given by the LM4702 IC, they state in the datasheet that the value can be between 10 to 35mV. if this value is too high for you, you may try to reduce this by externally bias the noninverting input pin of the IC with a high value resistor (about 1MOhm) connected to a trimmer which can provide the desired voltage to cancell the DC offset. there are also more complex methods to cancell the DC offset, but this involves modifications.
note that LME49810 has the DC offset about 10 times smaller.
as i remember, you mentioned before that you removed the input caps, and u connected directely to your preamp, which you said that it has no DC offset. maybe doesn't have big enough to be ale to measeure. but remember, that even 1mV offset at the input can cause those 60-70mV at output. this is amplified by the IC !!! try to connect capacitors at input or if you preffer to use without capacitors you may need a DC offset cancellation circuit.
I'm clearing the stock of the DA-1, TA3020 V2 amplifier and TA2022 Amplifier, customers which will purchase them untill 15 may can get them at the price displayed on my site, with shipping cost included. the total cost including shipping will be:
DA-1 80USD, TA3020v2 106USD, TA2022 56USD. also, customers who purchase at least 3 pcs from each model or combination of them, will get a free gift.
this offer will end in 15 may and is available in the limit of existing stock.
DA-1 80USD, TA3020v2 106USD, TA2022 56USD. also, customers who purchase at least 3 pcs from each model or combination of them, will get a free gift.
this offer will end in 15 may and is available in the limit of existing stock.
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