LED Leads & Transistor Leads are rusting away.???

[audioguru]

The earthquakes and rusting happen when you cheap buy Chinese junk.

 

[gophert]

Read subject line, It was originally about, LED Leads & Transistor Leads are rusting away??? Several people changes the subject to, Chinese rice batteries, copyright, battery label, PC boards, radio shack, types of batteries, steel wires, solder, moisture, etc & it want crazy after that. LOL. No 1 has mentioned earth quakes yet?

Don't you, gary350 have a schematic for a 1960's era seismograph based on an LM741 with LDR AGC and logarithmic response?

 

[Visitor]

Read subject line, It was originally about, LED Leads & Transistor Leads are rusting away??? Several people changes the subject to, Chinese rice batteries, copyright, battery label, PC boards, radio shack, types of batteries, steel wires, solder, moisture, etc & it want crazy after that. LOL. No 1 has mentioned earth quakes yet?

I guess like most of the advice here, sarcasm is also wasted on Gary.

 

[Nigel Goodwin]

Don't you, gary350 have a schematic for a 1960's era seismograph based on an LM741 with LDR AGC and logarithmic response?

I've got plenty of geophones, as used in seismographs - in fact I've just had to replace five - they didn't work properly in our application, and I suspect they are actually a different type from the rest of the batch.

 

[shortbus=]

I'm having a lot of trouble following this tread. I thought it was about flashing LEDs but then it was about welding with arteries but now microswitches? I'm so confused.

Typical of the Gary threads.

 

[shortbus=]

I hope Honeywell went out of business.

What does that have to do with your *Sunbeam* battery that you think is made in Canada?

 

[gary350]

The earthquakes and rusting happen when you cheap buy Chinese junk.

We buy what we can afford, we are retired, live on month SS check & eat cat food. Can't afford any Union made stuff.

Don't you, gary350 have a schematic for a 1960's era seismograph based on an LM741 with LDR AGC and logarithmic response?

no schematic of that.

 

[audioguru]

I am also a retired senior who lives on a government Seniors Pension. I receive Old Age Security payments each month because I lived in Canada all my life and since I am not wealthy I receive a Guaranteed Income Supplement each month. This government income has no income tax.
I receive a Seniors Discount on my property taxes and on my electricity bills.
My government pays for my doctors checkups and medicines. I had surgery and hospital stays for a heart attack and later, blood poisoning which were paid by my government.

I am careful with my money and do not throw it away like many people do. I ask for and receive a Seniors Discount at many stores.
Most items I buy are on sale. I buy large items mainly at Black Friday and Boxing Day sales.
I scan food store ads each week and buy many food products on sale but do not eat cat food. (I am shocked and sorry to hear you say that).

I NEVER buy cheap Chinese junk, most products purchased are high quality and are Union Made.

 

[gary350]

I started making a new circuit today with, new parts, new 60/40 solder, new batteries, new PC board, then I got side tracked.

2 old batteries in series are 2.7v I connected them to the joule thief circuit the LED lights up good. Joule thief works good on 1 new battery or 2 old low batteries. Joule thief circuit allows me to use all the old batteries & not buy new batteries for a while. Problem is joule thief needs an LDR so I added it to the circuit and it does not work with 2.7v. I changed the 56K resistor to 30K it still does now work.

I wonder how much power is left in 1 year old batteries that voltage has dropped from 3.2v to 2.7v. Joule thief so on and working good outside at the moment it will be interesting to see how long old batteries last. Tomorrow morning I will turn the switch off. Dark I will turn switch on again. It would be nice if LDR worked. WOW this Blue LED sure is bright it appears to be several times brighter than Red LED.

 

[DerStrom8]

...2 old batteries in parallel are 2.7v...

You mean series?

I suggest throwing a 100k VR in there instead of the fixed 56k resistor and adjust to find the threshold.

 

[gary350]

You mean series?

I suggest throwing a 100k VR in there instead of the fixed 56k resistor and adjust to find the threshold.

I fixed the typo thanks for pointing that out. LDR works good on this circuit so I added it to the other circuit but forgot voltage is not 3.2v like the other circuit.

 

[audioguru]

Be careful, reviews of Sunbeam "'Super Heavy Duty" (old carbon-zinc type) batteries from China say that they leak chemicals, produce very low power and are not worth it.

The 56k value for the base resistor of the power-switching transistor on the LED Blinker circuit is too high. If the batteries are brand new alkaline then the 3.2V supply minus the 0.7V base-emitter voltage drop produces a base current of only (3.2V - 0.7V)/56k= 45uA. The datasheet for the 2N3904 and nearly every other little transistor says that for it to saturate as a switch then its collector current shall be 10 times the base current. Then it will conduct well for a collector current of only 0.45mA which would cause the LEDs to be very dim.
The circuit has 470 ohms in series with each LED. Then the switched voltage is 3V which is turned on with the multivibrator driving a 2V red LED drawing a current of (3V - 0.2V - 2V)/470 ohms= 1.7mA (very dim LEDs). So the base current should be 1.7mA/10= 0.17mA and the base resistor value should be (3.2V- 0.7V)/0.17mA= 14.7k. Since the resistor value of 56k is too high then the switched voltage of only 2.4V shows the the transistor is not saturated.
Since the currents are very low, I think the resistor values were designed for the circuit to be powered from 9V to 12V.

 

[Visitor]

View attachment 128364

Two LEDs each on 50% of the time still has the same current draw as one LED on 100% of the time.... (which has been mentioned in this tread and the similar ones that have proceeded it.)

 

[gophert]

Two LEDs each on 50% of the time still has the same current draw as one LED on 100% of the time.... (which has been mentioned in this tread and the similar ones that have proceeded it.)

 

[audioguru]

That is why I blink each LED on my LED chasers for only 30 milli-seconds (long enough to see its full brightness) to save on battery power.

 

[gophert]

That is why I blink each LED on my LED chasers for only 30 milli-seconds (long enough to see its full brightness) to save on battery power.

And, asking for a friend, (Ha) the other one blinks 970 mSec?

 

[audioguru]

And, asking for a friend, (Ha) the other one blinks 970 mSec?

Nope, I said each LED for 30 milli-seconds. Thanks for the head banging animation, it is a good one.

 

[gary350]

Be careful, reviews of Sunbeam "'Super Heavy Duty" (old carbon-zinc type) batteries from China say that they leak chemicals, produce very low power and are not worth it.

The 56k value for the base resistor of the power-switching transistor on the LED Blinker circuit is too high. If the batteries are brand new alkaline then the 3.2V supply minus the 0.7V base-emitter voltage drop produces a base current of only (3.2V - 0.7V)/56k= 45uA. The datasheet for the 2N3904 and nearly every other little transistor says that for it to saturate as a switch then its collector current shall be 10 times the base current. Then it will conduct well for a collector current of only 0.45mA which would cause the LEDs to be very dim.
The circuit has 470 ohms in series with each LED. Then the switched voltage is 3V which is turned on with the multivibrator driving a 2V red LED drawing a current of (3V - 0.2V - 2V)/470 ohms= 1.7mA (very dim LEDs). So the base current should be 1.7mA/10= 0.17mA and the base resistor value should be (3.2V- 0.7V)/0.17mA= 14.7k. Since the resistor value of 56k is too high then the switched voltage of only 2.4V shows the the transistor is not saturated.
Since the currents are very low, I think the resistor values were designed for the circuit to be powered from 9V to 12V.

This circuit works good. When batteries get low about 2.8v to 2.7v it stops working. So maybe I need to test circuit with a lower value R1 resistor with 2.7v batteries. Maybe I can increase battery life a little bit more by lowering R1. I will test this in about an hour.

I increased the original value of R3 & R6 to increase battery life from 9 months to 12 months. After dark I walked 180 ft to the street to look at LEDs they were very bright with the original R3 & R6 values. I reduced LED brightness so they could still be seen easy this increases battery life. R3 & R6 are perfect now. I think the original value of R3 & R6 was 330 ohms.

I tested several LDRs they are not all the same. In Light they test 150 to 500 ohms. In Dark they test 200K to 400K.

 

[Visitor]

 

[gary350]

Be careful, reviews of Sunbeam "'Super Heavy Duty" (old carbon-zinc type) batteries from China say that they leak chemicals, produce very low power and are not worth it.

The 56k value for the base resistor of the power-switching transistor on the LED Blinker circuit is too high. If the batteries are brand new alkaline then the 3.2V supply minus the 0.7V base-emitter voltage drop produces a base current of only (3.2V - 0.7V)/56k= 45uA. The datasheet for the 2N3904 and nearly every other little transistor says that for it to saturate as a switch then its collector current shall be 10 times the base current. Then it will conduct well for a collector current of only 0.45mA which would cause the LEDs to be very dim.
The circuit has 470 ohms in series with each LED. Then the switched voltage is 3V which is turned on with the multivibrator driving a 2V red LED drawing a current of (3V - 0.2V - 2V)/470 ohms= 1.7mA (very dim LEDs). So the base current should be 1.7mA/10= 0.17mA and the base resistor value should be (3.2V- 0.7V)/0.17mA= 14.7k. Since the resistor value of 56k is too high then the switched voltage of only 2.4V shows the the transistor is not saturated.
Since the currents are very low, I think the resistor values were designed for the circuit to be powered from 9V to 12V.

Now I am talking about the Joule Thief circuit with only 1 LED. This circuit works perfect with 1 new 1.5v battery. If I use 2 low battery from the (other 2 LED circuit) on this 1 LED circuit the Joule Thief circuit work perfect on 2.7v batteries. 2 low batteries 1.5v Joule Thief works perfect.

The Joule Thief circuit will not work with the LDR circuit. I tested the Joule Thief with 2.7v it works good but when I add the LDR, resistor, transistor, it stops working. I replaced R1 & R2 with variable resistors I can not make Q1 on the circuit work. I tested several 2n3904 & several 2n2222 transistors none of them work. I tested the transistors with meter they test good. With R1 at 500K no value of R2 will turn on Q1. Lower R1 value no value of R2 will turn on Q1. Remove, Q1, R1, R2, then the circuit works perfect on 2.7v or 1.5v.