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  1. G

    Trouble with TPA 3116 amplifier powered by 6S 25.2V 15A 18650 Charger

    I am having trouble getting my DAMGOO TPA 3116 Bluetooth amplifier board to power up from an Anmbest 6S 25.2V 15A 18650 charger PCB BMS protection board. The battery pack is wired according to instructions with six 18650 rechargeable batteries. I have charged the battery pack. It tests at 19.4...
  2. Y

    2*50w+100w Amplifier with 5w tweeters and 100w subwoofer

    I want to make two new speakers fo my computer. I have found a amplifier with 2*50w+100w and 3 drivers: one subwoofer 100w 8 ohm and two tweeters 5w 8 ohm. I don't know why but i think i'm about to blow up my tweeters. I can't find a solution to decrease the wattage of the 50w output. Can you...
  3. F

    Analog of operational amplifier

    Hello everyone. I need help to find analog of operational amplifier. Original one broken on circuit of my 3D printer. I found some similar parts, but i am not sure, that i right about this parts, Photo of original amplifier below.
  4. A

    3rd order Sallen-Key High-pass Filter

    Hi all, I simulated a 3rd order Sallen-Key High-pass Filter and got the frequency response shown below (Fc = 6Hz) Now I built the same circuit in practice, but I am noticing that at around 10Hz the output signal is being amplified, with the most likely cause being that the frequency response i...
  5. S

    Help with Bluetooth audio receiver board CSR8675

    So I bought this cheap bluetooth receiver along side a class-d amplifier board in hopes of connecting the two together to make a portable bluetooth speaker. This chinese amplifier board uses 12-24V dc and has a power out connection which provides 5V dc (probably specifically designed for a...
  6. H

    I can't find the problem. 2 stages amplifier with op amps.

    I have the following circuit. I have some problems and I can't identify the reason. 1.Why I have such a distorsioned output voltage? 2.Why Vmax is aprox is 25V ,but Vmin is 29V?
  7. E

    Speed Signal Booster - low pulse to high

    Hi I need help to boost low pulse to high. I have a sensor which detects no of pulses per second. For some vehicle it couldn't detect it is a low pulse signal. Please suggest some circuite which can boost the signal.
  8. O

    What does 'B' means in this datasheet formula?

    Hi everyone I'm not an EE by any means, i guess this could be a simple question but... What does the letter 'B' stands in this datasheet formula? It's found here, page 10 https://www.st.com/resource/en/datasheet/cd00000128.pdf
  9. hesam_m

    Amplification of the signal decay

    I should amplify a low impedance signal with the peak of maximum 1.4V. The tricky part is that the signal itself is not important but the tail of the signal is important which might show some decay (falling edge could reach to zero sooner or later than normal) and these signal decay variations...
  10. DZ12488

    From Mini Speaker To high db Piezo buzzer Alerting Device

    I need some advice on what is the quickest way to change the alert signal output through a amplifier to run a fixed tone transducer with on board tone driver ? Problem to start with is my customer has issues of the speaker alerting device on this agricultural implement monitor is too quiet . So...
  11. J

    Replacement for AD630 for the purpose of Lock-in Amplification

    Hi, I am trying to build a lock-in amplifier circuit using AD630. But the signal which I wanted to detect is in the megahertz range and AD630 is not functioning in this region. So, is there any device which can do lock-in like AD630 but in a higher frequency region? Thank You.
  12. M

    One speaker is picking up radio module noise

    I currently made a module to my project which isn't quite functioning correctly. It's 4 distinct parts on one board. The radio I/O, the two independent sound amplifiers out of the LM386's and the RFID card reader. This is the circuit: The actual inverter IC I used is 74HCT04 because it...
  13. J

    Subthreshold Transconductance Amplifier Design

    As part of a broader project, I am designing IC circuit using CMOS to one of the first steps I'm working on is the filtering a series of pulses with of the noise. The actual pulses are around 1 kHz so I am implementing 2nd order sallen-key high pass filter. Since the capacitance is limited to...
  14. sr13579

    Is it safe to use a 5V-1A USB(Samsung mobile) charger for lm386?

    Hello everyone, A brother from my hometown told me to make a mini amplifier that can pull the power out from a USB charger(or PC USB). I happened to working on a logic gate IC and burned the IC while using a USB(power bank) charger. I want to know is it safe to use a 5V-1A charger to power the...
  15. D

    Photodiode current measurements

    I am trying to build transconductance amplifier circuit to obtain values of the reverse biased photodiode (PD) current in order to estimate some of the LED characteristics. At first, I have used the scheme named “Recommended Zero Biased Circuit” from page...
  16. A

    Stable DC power supply point for Ultra Low Noise Amplifier (ULNA)

    Hello good people, I need help. I'm posting a schematic of an ultra low noise amplifier. It is to be powered by batteries. For that reason, I need a stable DC solution in the place of R4 resistor. I was proposed to achieve that by using another JFET and an integrator circuit, but I am not...
  17. O

    Amplifier for 4 piezo mics to 4 mono speakers

    Hello! I am an absolute beginner learning electronics by working my way through the Make:Electronics book by Charles Platt. I have a long way to go, so I am hoping someone can give me some guidance on a project I am working on now. I would like to have 4 small piezo microphones independently...
  18. sr13579

    How to increase bass on speaker?

    I have a 8ohm 30W speaker and lm386. I don't know much about the internal structures of lm386. I want only bass sounds(frequencies) in that speaker. How can I do that? And I also want to know how to smoothen the high frequency sounds?
  19. Mosaic

    Class E amp in LTspice

    Hi All: I spent a few hours tweaking this using common parts to about 90% efficiency. It can do more power out with a > 36V supply. No AM modulation , yet.
  20. E

    LTSpice amplifier oscillation. Why DC and AC analysis don't match?

    Hello. I'm simulating a simple amplifier to be used as input and VAS stages for an audio power amp. It uses negative feedback. The gain is 20, fixed by the ratio of R4 / R3. I know this kind of circuits usually need some kind of frequency compensation to avoid oscillations. The circuit is...
  21. A

    How to connect stereo (2 channel) signal to 4 channel analog inputs

    Hi Team, I'm using TAS5414C-Q1 IC for audio amplifier. It has 4 channel analog inputs. I'd like to interface 2 channels from a 3.5 mm jack to these 4 channel inputs. How do I achieve this. Should I parallel the inputs. Is the below pic right way to connect in this regard...
  22. A

    volume/output power control using a knob in TAS5424C-Q1

    Hi Folks, It seems that the gain in the IC TAS5424C-Q1 can be controlled using I2C protocol. But I'd like to keep it simple using a hardware (rotatory knob). Is it possible to control the volume and output power using hardware control such as a rotatory knob generally used in car head units...
  23. throbscottle

    NOS Transistor with brittle leads

    Happy Thursday everybody! I managed to get what is probably a genuine Toshiba 1996 2SA1302 with green epoxy, to repair a PA, and started bending it's leads to match the original which have a semi-circle bent into them, presumably to allow for thermal expansion. They creaked and crackled a bit...
  24. E

    Class D amplifier for arduino

    I was playing about with transistor amplifiers nd I built this class D amplifier intended for use with the arduino ( or any other microcontroller) https://siliconjunction.wordpress.com/2017/02/28/class-d-amplifier-for-the-arduino/ Thanks Matt!
  25. B

    need amplifier circuit for M831 Electronic YZC 131 5kg weighing weight scale pressure sensor load ce

    We need to convert load cell output(millivolt) to (4-20)milliamps to give input to the PLC. Is there any IC or circuit diagram to directly convert millivolt to milliamps?

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