Circuits FAQ

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Tuesday, December 01, 2020

Ultrasonic Range Meter

I have attached a document of the circuit explanation of my ultrasonic range meter. But now I want to know if Im going to insert with in series with my 1M ohm resistor for the feed back of the op-amp to tune it for perfect 100db if the pot is not going to cause a bit of inductance due to the high frequency. 

Can you please help me with some calibration features/tips I can added into my circuits Thanks and regards 

WS SA


Circuit explanation of Ultrasonic Range Meter unit 

oscillation circuit to control the sending-out time of the ultrasonic pulse. The time of the oscillation pulse can be calculated by the following formula. Actually, with the error of the parts, it is different from the calculation a little. 

Ultrasonic Range Meter

Circuit explanation for Ultrasonic Range Meter

The ultrasonic signal which was received with the reception sensor is amplified by 1000 times(60dB) of voltage with the operational amplifier with two stages. It is 100 times at the first stage (40dB) and 10 times (20dB) at the next stage.

Digital Music Player with Amplifier

I need to know as making an amplifier with a port USB as music storage in a memory Flash, which circuit integrated as independent DAC can use could give me some diagram that could use. Greetings and respects 

Gonzalez RC


This is a very old emial from my thunderbird archive.

Digital Music Player with Amplifier
 

Try this MP3 Player with LCD Display

This project is a stand alone MP3 player, designed for home, car, or portable use. It plays a group of MP3 files stored on a standard or laptop IDE hard disk drive... hundreds of hours using even today's low-cost drives.

The firmware is available under the GPL, for anyone who want to really customize the player. High quality audio output is provided by a 24 bit DAC, using both standard line-level outputs and an amplified headphone output.

Sunday, November 08, 2020

Digital weight Indicator - Strain Gauge

I need some details of a digital weight Indicator.
mail from CA

Digital Weight Indicators and Weighing Scales use Strain Gauges mounted on a Stressed Beam, Cantilever or Plate which is also Elastic, means springs back to old shape.

Digital weight Indicator - Strain_gauge

Strain Gauges are bonded to these plates and connected in a Wheatstone bridge circuit. The output of these are very low, as less as 5mV. These are amplified close to the sensor and usable outputs in volts, like 0-10V are used to display the parameter or control the systems.

Fluids Weights are measure with pressure sensors also. Which also have a mini strain gauge or piezoelectric sensor to convert weight to millivolts.

delabs

Wednesday, November 04, 2020

What is Saturation in Transistors

Date 8/30/06 Simon and delabs
Simon: hello,
delabs: hello

Simon: we have many meanings for saturation,
delabs: means turning on, also means no longer linear, or it is got fixed up, not varying in accordance to any formula

Simon: that is what is concluded of. but we just wanted to be sure.
delabs: like you put salt in water. after some time no more salt can be dissolved, that is the state of saturation, In Electrical, no more relationship with V - I - R. Any increase in voltage or reduction it is same

Simon: thanks
delabs: anytime

What is Saturation in Transistors

Bipolar transistors are so named because their operation involves both electrons and holes. These two kinds of charge carriers are characteristic of the two kinds of doped semiconductor material; electrons are majority charge carriers in n-type semiconductors,

Sunday, November 01, 2020

Building a mV Milli-Volt Calibrator Source

Hi, I am trying to build this mV source that you have drawn on your site. It requires a 5vdc power source with a 1k resistor in line with a 10K pot. Your schematic shows also with the pot a 10k resistor and a 100E component which I have no idea what that is.

My question to you is... does the 10K pot include the 10K resistor and the 100E component or are they separate from the pot? If they are separate, what is the 100E component?

Thanks, KN USA

Dear KN

I would like to know the Circuit File you were referring, i have many on my site for instruments.  Let us understand the Theory so you can build your own.

First - You need a Regulated Power Supply for these circuits to be accurate enough. We do not need things like 0.01% for Industrial Electronics or Field Calibration. You can always keep one of these accurate ones in your Lab.

Building a mV Milli-Volt Calibrator Source 

Second - Now to bring down the Voltage of say 5V to mV, we need to Attenuate right. An attenuator contains Two Resistors. The High Value - like 1K is a Fixed MFR 1% Resistor. This faces the 5V and Then comes a Multiturn Pot, preferably Bourns or Spectrol 10 turn, This is 10K. These two form just the One part of the attenuator.

See another design here  Current Source mA for calibration

Monday, October 12, 2020

Up-Down counter-timer

(A question answer thread of delabs.net, nearly a decade old)

Presettable Up-Down counter-timer

I am looking for a schematic for a pre settable Up/Down counter that I can build for my church. It needs to be 5 decades. From 0:00:00 to 9:59:59. I ran across your web pages while searching for such a schematic. Can you help me out?

EE



Presettable Up-Down counter-timer-Answer

It appears from the "9:59:59 " you have mentioned, what you need is a timer.It it a count up and count down timer you need, like a clock ?

Can you explain to me how you plan to use this circuit in the church.Visit the links below and see if that is what you want.

delabs


Presettable Up-Down counter-timer-Reply 

Thanks for the links. What I need this count down timer for is to allow speakers at the church to know how much time is remaining of their presentation. All of our speakers are taped for later use or review. The speakers giving the presentation usually go over their time limits for the audio tapes. With this unit I am trying to build time can be entered by preset thumbwheel switches. The counter is then started and times out when the counter reaches 0:00:00.

What makes this count down timer different is there will be two seperate displays. A one inch set of seven segment LED's will be in the main console with the rest of the logic. There will also be a 2.5 inch set of seven segment displays remotely connected (anout 3 feet away). The large displays will be what the speakers will see. The small displays will be in the control booth.

I already have the following items gathered up. I am hoping to use these components if I am able. I have the MC14029, the MC14513, the Allegro UDN2597A (to drive the large LED's), the Dallas Semi DS32KHz time base, the MC14020, the MC14013, the large and small LED displays, and the thumbwheel switches (set to 9:59:59 maximum)

I also have some MC14011, MC14490 (Hex Debounce Switch Controller, MC14049, and the R's and C's necessary to complete the circuit.

Does this explain what I am trying to do? I think the MC14029 counters can be used to do all the counting and store the preset values. All I have to do is add the reset at 6 for the tens of seconds and the tens of minutes. However, I don't know how to connect the logic?

The DS32KHz, MC14020 and MC14013 will generate the 1 Hertz (1PPS) signal. That is about all I currently have. That is why I need some help

EE


Presettable Up-Down counter-timer-Answer

below are two circuits in pdf format see if they are ok see... Digital Circuits-2

Circuit 1 - Digital Timer Clock With Preset using Thumbwheel switch.


Circuit 2 - 1 Hz or 1 pps crystal clock using CD4060 and 32768 Hz Crystal.


They have not been tested much... The 4513 control pins 8-4-5-3 connections verify, as i did not get the datasheet.

the circuits will work as concepts are right, but some tweaks in R C values may be required.
the R C values can only be corrected if you have problem in making it work.

the main problem in the R C values may be related to "the reset at 6 for the tens of seconds and the tens of minutes". tell me what changes you may want. this is a presettable count down timer upto 99.59.59 hours.minutes.seconds

delabs

Temperature Meters with Analog Recorder Output

I would like to know if you offer a monitoring solution that will constantly measure ambient (air) temperature (say, 0 to 150°F), and provide a corresponding DC voltage output of either 100 mV, 1 V, 5 V, or 10 V. Do you make a unit that can be configured to do this?

Mail From JPE - WV - US


Analog outputs were very popular as they are inputs to Strip Chart Recorders, Later they had an extra use for PC Based Data Acquisition, data Loggers and PLC. Now we have Instruments with digital and wireless outputs too.

Temperature Meters - DP116 - Omega
 
Economical 3/64 DIN panel meter that has a full size 0.56" green or red LED display, with a built-in analog output and display hold capability. 3 1 /2 Digit Display.

Features Include
  • Thermocouple and RTD Input
  • Full-Size 0.56" (14.2 mm) LED Display
  • Analog Output Standard
  • 1 /8 DIN Panel Adaptor Standard

Economical Digital Meters DP18 - Omega

Economical Digital Meters DP18 - Omega

The DP18 series is a complete family of panel meters with input cards for voltage, process and temperature measurement and control. The signal conditioners for voltage will measure ac or dc voltages or true RMS.

Modular Design, Options for Alarms, Analog Output of Communications, 3 1/2-Digit LED Available in Red or Green Displays

delabs

Saturday, October 10, 2020

HV low current device for testing

New device and needed E-instrumentation > > Have you a controlled e.g. 0-10 kV and 0-100 mA device

MR EU


HV low current device delabs

Do you mean a Variable 0-10 kV with 0-100 mA Current Variation.

Yes, i have made such supplies for Testing Capacitor Insulation long ago. Though The limit of current was around 10mA. What you are indicating is a 1 Killowatt HV supply. Needs safety Precautions. 

delabs