(editor’s note: Intrigued by the problem? Have a question or another solution? Then click the “Read more” link and follow the conversation on EDAboard.com or log in to EDAboard and participate in the analog IC forum threads.)
Battery voltage warning – I have 2 circuits. The idea is to show a warning when the battery drops under 3.3V from 4.5V. Do you think they will work. One of them will turn off the diode when the voltage drops, the other one will start the diode when the voltage drops. I am worried the diode will burn, because it’ss connected directly to ground or because the current or voltage is too high. Read more
Difference between BT138 and BCR12PM Triacs – I’m busy fixing my washing machine and it has 2 triacs for driving the tub motor in different directions. The manufacturer has put BCR12PM triacs in for both directions. One of them has given the ghost… My local supplier has given me a BT138, from what I can see in their specs, the BT138 should be ok. Both are 12A rated, both at 600 Vdrm, which was the main thing I looked at3.vI have 2 other BTA24 Triacs rated at 25A, but won’t use them if I can help it. Read more
Circuit to boost output of op amp – I have been thinking about making my own SMU like device (Source Measure Unit) and for that I need to take a signal from an op amp and boost the current capability a huge amount. Is it impossible to use an op amp in an application like this? Read more
Type of transistor amplifier – What class amplifier that is? Read more
Transceiver ultrasonic sensor problem – I am working on ultrasonic transceivers for my range finder project. My main goal is to achieve this project with one sensor. Before this, I’ve achieved range finding with receiver/transmitter sensors separately. It worked well but as I said I need to finish this with transceiver sensor. Here is my schematics that I drew for one sensor. My driver circuits works fine. It generates around 100Vp-p. But the problem is there was no echo signal coming through amplifier circuits. Read more
Reason for voltage return in transformer? – I have a circuit with two transformers, each of which has two phases in the primary winding. But the problem is when I disconnect one of the phases (for example L1) from Tr2, there is still voltage in that disconnected phase that is due to return voltage of Tr2. What is the reason for this? Read more
Closed loop question and time response – I would like to know if this statement/question makes sense: the closed loop is taking too long to react. Can someone tell me what this exactly means? Another question, how is the closed loop related to the settling time? Read more
Want to design a Source Measure Unit (SMU) – While I went through designing a DC-DC converter (not done yet), I became aware of SMUs or Source Measure Units and I immediately realized that I want one of those (minimum 2 channels), but the price tag of such a device is too prohibitive for me to be able to get one. But I don’t see a reason why I wouldn’t be able to design my own, and I am somewhat surprised to find that there is pretty much no such design on the web. Read more
Variable frequency PWM to analog circuit? – I need to convert a PWM to an analog signal. But the issue is, the frequency of the PWM may change so the RC-filter option is not preferred. What kind of circuitry would be appropriate for this? By the way, there exists an IC named LTC2644, which operates exactly as I want but not meeting my frequency requirements (5 to 500Hz frequency PWM). Read more