Search found 2766 matches

by haklesup
Thu Dec 13, 2018 12:15 pm
Forum: General Discussion
Topic: Water Leak
Replies: 8
Views: 962

Re: Water Leak

Check out this one, super easy to install monitor https://streamlabswater.com/ they may have a valve eventually too
by haklesup
Thu Dec 06, 2018 11:31 am
Forum: General Discussion
Topic: ok,, New Project time,,,
Replies: 31
Views: 4338

Re: ok,, New Project time,,,

Since you have access to a proportional voltage, the hard part is done. If you want Old School then get a mechanical ammeter movement, figure out the resistor network to get the needle to deflect full scale at 4V and replace the graphics behind the needle with a custom scale 0 to 100%. (assuming it ...
by haklesup
Fri Nov 30, 2018 3:39 pm
Forum: General Discussion
Topic: need help to find blue led bulb
Replies: 17
Views: 1475

Re: need help to find blue led bulb

I did reconsider the LED breakdown voltage after I posted, it would be better than 5V but probably insufficient for 120V. Adding another rectifier in series would work but in any case it does appear there are bulbs of this type on the market though not cheap. Not sure how $20 compares to "originals"...
by haklesup
Fri Nov 30, 2018 10:55 am
Forum: General Discussion
Topic: need help to find blue led bulb
Replies: 17
Views: 1475

Re: need help to find blue led bulb

Well an LED is a diode so it in itself is a rectifier. Assuming you want to bias at 5mA (adjust accordingly maybe that's a bit low for this application) then 120V/.005 =24k resistor, .005^2*24000= 0.6Watts I would assume the incandescent bulb was more than that at least 6W, the base should be able t...
by haklesup
Thu Nov 29, 2018 4:45 pm
Forum: General Discussion
Topic: need help to find blue led bulb
Replies: 17
Views: 1475

Re: need help to find blue led bulb

you can use an LED for 120VAC, all you need is a sufficient dropping resistor, it's not as safe as 12V though, Blue LED in T1 package or various COB formats are available and pretty bright. I'm still unclear on the actual bulb base you are looking for. What is the bulb number of the original? is it ...
by haklesup
Thu Nov 29, 2018 3:25 pm
Forum: General Discussion
Topic: Some questions met when designing PCBs
Replies: 2
Views: 548

Re: Some questions met when designing PCBs

From a practical standpoint, it often boils down to what are the design rules as set by the place you are going to have them built. Knowing your vendor, their pricing rules and what design rules go with what prices will help you buy at a reasonable price. and setting the right design rules for the D...
by haklesup
Tue Nov 20, 2018 10:34 am
Forum: General Discussion
Topic: Edenpure Classic space heater...NOT LEVEL
Replies: 17
Views: 4610

Re: Edenpure Classic space heater...NOT LEVEL

I've not tried one of those so called IR heaters, does it perform differently that a plain old space heater. To me a Watt is a Watt no matter how you put it into the air. OTOH, the configuration of the heat sink does effect the efficiency of how the heat flows. In a regular space heater, the element...
by haklesup
Tue Nov 20, 2018 10:18 am
Forum: General Discussion
Topic: How to select the Gate Drive Resistor
Replies: 4
Views: 527

Re: How to select the Gate Drive Resistor

For the most part, the gate of a FET is an open circuit so one does not expect much current to be flowing at any time. In general the Gate resistor is a high value, either arbitraritrarily high like 10M or calculated based on AC response. In DC operation, the current is essentially 0A and the resist...
by haklesup
Thu Nov 15, 2018 4:54 pm
Forum: General Discussion
Topic: Opus BT-C3400 lipo charger / tester
Replies: 9
Views: 820

Re: Opus BT-C3400 lipo charger / tester

I found it in this manual https://images-na.ssl-images-amazon.com/images/I/51TCfcbvBaL.pdf DISPLAY Selection LCD Display Backlight Control. Press and hold the DISPLAY button for more than 5 seconds to toggle the backlight mode. To turn on the LCD Display Backlight press and hold the DISPLAY button f...
by haklesup
Thu Nov 15, 2018 4:49 pm
Forum: General Discussion
Topic: IC compatibility Question
Replies: 1
Views: 398

Re: IC compatibility Question

They have the same logic function but internally they are very different. The HCT part is CMOS and the LS part is Bipolar technology. The input and output logic levels are different. Consult the DC specifications page of the datasheet and look at the VIL, VIH, VOL and VOH levels. In most cases the C...
by haklesup
Fri Nov 09, 2018 11:52 am
Forum: General Discussion
Topic: Microphone in a bubble...
Replies: 7
Views: 770

Re: Microphone in a bubble...

an electret mic is not the highest fidelity options on todays market anyway. Its handy because it can be used with Voltage boas rather than current bias. Most of these could probably be waterproofed by simply putting tape over the sound port and sealing the electrical contacts in epoxy. They may alr...
by haklesup
Fri Nov 09, 2018 11:44 am
Forum: General Discussion
Topic: How select the Commonly Used Electronic Components
Replies: 5
Views: 748

Re: How select the Commonly Used Electronic Components

Capacitors are among the most confusing parts to select because there are many unfamiliar parameters delineating product lines and quality/reliability grades. This as well as similar values and form factors over different construction types (electrolytic vs tantalum for example). Best place to start...
by haklesup
Thu Nov 08, 2018 11:17 am
Forum: General Discussion
Topic: Microphone in a bubble...
Replies: 7
Views: 770

Re: Microphone in a bubble...

All of those materials would impede sound waves and attenuate the sound somewhere along the spectrum. Even considering an idealized flexible membrane, you now have 2 air masses coupling through the membrane with one being much much smaller than the other. Since air on both sides is compressible, no ...
by haklesup
Tue Oct 23, 2018 5:09 pm
Forum: General Discussion
Topic: Lithium Ion charger hack..
Replies: 7
Views: 843

Re: Lithium Ion charger hack..

following the link from the schematic page to the part you do get a reference schematic with the NTC included but you need more than that device, you will need the voltage divider it forms with R1 and R2. the web page says "Thermal feedback regulates the charge current " So I presume the voltage on ...
by haklesup
Mon Oct 22, 2018 5:37 pm
Forum: General Discussion
Topic: Amplifier LM358—classical circuits
Replies: 5
Views: 817

Re: Amplifier LM358—classical circuits

not surprising, some of those circuits are very incomplete. If you are interested, continue studying op amps in general, there will be many many references. Once you understand the basics of applying them as Amplifiers, filters, current sources, comparitors etc then you can start looking at the spec...